Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
Earth set itself grimly to meet them with corrosive fire, determined to blast them back to the stars. But they erred in thinking the Old Ones were too big to be clever. "Suppose we settle this argument about humanity," said Knof Llud and had changed its color from a dazzling blue through white to the normal yellow, of a GO sun. That was the Doppler effect as the star's radial velocity changed relative to the Knof Llud stiffened. The the ship had decelerated. They had seen many such stars come near out of the galaxy's glittering backdrop, and had seen them dwindle, turn red and go out as the , launched toward Arcturus and the Quest III drove on its way once more, lashed by despair toward the speed of Knof Llud, the Eyes lifted from the vision screens to interrogate Knof Llud them with an impassive countenance, and announced quietly, "We've sighted Earth." A feverish buzz arose were forgotten and exaltation prevailed. Knof Llud smiled wryly. The rest of the little speech he had been about shrewdly, of Knof Jr. and Delza, who save from pictures could not Quests returned successful, or if they returned at all. And we don't know what changes have taken place on Earth. It's Knof Llud and the hope of success in man's mightiest venture had dwindled, so the Quest III in interstellar flight while report to whatever powers might be on Earth now—if such powers were still interested. Llud selected a spool from among the earliest. It was one he had made "It is cheering to note that the crew seems only more resolute. We go on to Capella its spectrum, so like our own Sun's, beckons. If success comes there, a century will have passed before we can return to Earth friends, relatives, all the generation that launched the Presently Knof Llud switched off that younger voice of his and leaned we cannot betray the plan.... energy stores that went into them, left Earth's economy drained and exhausted. Only once in a long age does mankind rise to such a selfless and transcendent effort—the effort of Egypt that built the pyramids, or the war efforts of the nations in the last great conflicts of the twentieth century. "Looked at historically, such super-human outbursts of energy are the result of a population's outgrowing its room and resources, and therefore signalize the beginning of the end. Population can be futile as pyramid-building, less practical than orgies of slaughter to reduce pressure.... In any case, it would be impossible to transport very many people to other stars but Earth could at least go into expanding limitlessly into the Universe.... "Hopeless, unless we find planets!" Knof Llud shook his head sorrowfully and took off the spool. That "According to plan, the Quest III could achieve a velocity that would take us there without dying of senility of aging too greatly. It would be a one-way journey—even if enough fuel remained, there would be little point in returning to Earth after overpopulation. "Why go back, then with the news of our failure? Why not forget about Earth and go on to Omega Centauri? What use is quixotic loyalty to a of homesickness, though they know with their minds that everything that was once 'home' has probably been swept away.... "It doesn't matter. Today I gave orders to swing the ship." Savagely Knof Llud stabbed the button that shut off the speaker. Then he sat for a time with head resting in his hands, staring into nothing. ... for my purpose holds To sail beyond the sunset, and the baths Of all the western stars, until I die. Llud sighed. He still couldn't say just why he had given the order to turn back. The stars had claimed his heart—but he was still a part of Earth, and not even nine hundred years of space and time had been able to alter that. Knof could go camping, and lie on their backs at night and gaze at the unhurried. Whatever it had been was past, and he had a good idea collision armor was nonmaterial and for practical purposes invulnerable. Just as he took his finger off the button that opened the door, the frowning—surely a meteoroid impact wasn't that serious. Coincidence, maybe—it might be Zost Relyul calling as instructed. we're being attacked!" "Sound the alarm. Emergency stations." He had said it automatically, then felt a curious detached relief at the knowledge that after all these years he could still respond quickly and smoothly to a crisis. There was a moment's silence, and he heard the alarm start—three "Now—attacked by what?" sixth now." Repeated blows quivered the Quest III's framework. The navigator said, obviously striving for calm, "They're light craft, not "If they're that small," said Knof Llud deliberately, "they can't carry In the open doorway he almost fell over his son. Young Knof's eyes were Quest III shuddered, again and again, under blows that must have had millions of horsepower behind them but it plunged on toward Earth, its mighty engines still steadily braking its interstellar velocity. To a man, the ship's responsible officers were already on the bridge, Knof Jr. flattened himself against the metal wall and watched silently. can't touch us as long as our power lasts—or until they bring up some bigger stuff." The mild shocks went on—whether from projectiles or energy-charges, would be hard to find out and it didn't matter whatever was hitting Quest III's shell was doing it at velocities where the distinction between matter and radiation practically ceases to exist. But that shell was tough. It was an extension of the gravitic drive all space inside its field were a single perfectly elastic body. A meteoroid, for example, on striking it rebounded—usually vaporized by the impact—and the ship, in obedience to the law of equal and opposite forces, rebounded too, but since its mass was so much greater, its deflection was negligible. would have felt nothing at all of the vicious onslaught being hurled against them, save that their inertialess drive, at its normal thrust of two hundred gravities, was intentionally operated at one half of one per cent efficiency to provide the illusion of Earthly gravitation. The Quest III bored steadily on through space, decelerating. Even if one were no fatalist, there seemed no reason to stop decelerating or always attacking, with the senseless fury of maddened hornets. The Knof Jr. whooped ecstatically and then subsided warily, but no one was Quest III , except that they were rocket-propelled and of far lesser size. Their Tiny, deadly hornets with a colossal sting. "Robot craft, no doubt," said Knof Llud, but a chill ran down his spine conquer. constant arrival of fresh attackers, while others raced away into space, presumably returning to base to replenish their ammunition. That argued a planned and prepared interception with virulent hatred behind "We'll have reached Earth before then," Gwar Den said hopefully. "If they don't bring out the heavy artillery first." Knof Jr. burst out, spluttering slightly with the violence of a repeating on each the same brief recorded message: "Who are you? What do you want? We are the interstellar expedition Quest III ...." And so on, identifying themselves and protesting that too. Once more Knof Llud had the insidious sense of his own nerves and muscles and will weakening along with the power-sinews of his ship. Knof Llud whirled to the radio apparatus, his weariness dropping from last. The two other interstellar expeditions that went out have already returned and been destroyed, as you will soon be—the sooner, if you continue toward Earth." Knof Llud's mind was clicking again. The voice—which must be coming from Earth, relayed by one of the midget ships—was not very smart it

<question>:
What was Knof Junior’s plan to defeat the attackers?

<options>:
A Talk to the attackers
B Replenish with fresh crew to fight
C Wait for the attackers to make a mistake in anger
D Release the gravity impulses

<answer>:

C