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

<passage>:
"Now Fweep ain't the brightest creature in the Universe, so he can't Extensive research did not uncover any evidence that the U.S. copyright "That's the problem. All we got to do is figure out the answer. No use flivver was shaped like a crude bullet, blunt at one end of a fat cylinder and tapering abruptly to a point at the other. It had been slapped together out of sheet metal and insulation board, and it sold, fully equipped, for $15,730. It didn't behave like a spaceship, either. As it hurtled down, its speed increased with dramatic swiftness. Then, at the last instant before impact, it stopped. Just like that. A moment later, it thumped a last few inches into the ankle-deep grass and knee-high white flowers of the meadow. It was a shock of a jar that made the sheet-metal walls boom like thunder machines. The flivver rocked unsteadily on its flat stern before it decided to stay upright. Then all was quiet—outside. "Now, Grampa," Fred soothed, but his face was concerned. Fred, once called Young Fred, was Grampa's only son. He was sixty and his hair had begun to gray at the temples. "That landing was pretty rough, Junior." less than that of Mercury and yet a gravitational pull as great as Earth." openings in the top. One of the openings was lighted. "That landing made me push the wrong button and the dad-blasted thing beat me again." "And who spent it all trying to invent perpetual motion machines and go searching for uranium and habitable worlds all through this deadly Earth, didn't you? What's the game?" "That's simple," Four said without hesitation. "The winning strategy is "No use bothering the others yet," Junior said, his face puzzled. "You see, I didn't let the flivver drop those last few inches. The polarizer quit." "Quit!" "That's not the worst. I tried to take it up again. The flivver—it won't budge!" The thing was a featureless blob, a two-foot sphere of raspberry gelatin, but it was alive. It rocked back and forth in front of Four. face. "Four! Get that nasty thing out of here!" impatiently. "Get it out!" "If it's Four's friend," Reba said firmly, "it can stay. If you don't "Fweep?" asked the blob. "Sure," Four said. "Go ahead, fweep—I mean sweep." Swiftly the sphere rolled across the floor. Behind it was left a narrow path of sparkling clean tile. Grampa glanced warily at Joyce's door to make sure it was completely submerged in this family too long brides, the three jealous husbands, the river and the two-passenger of the cannibals can row. If the cannibals outnumber the missionaries—" Grampa reached down to pat it. For an instant, his hand disappeared into Fweep, and then the alien creature rolled away. This time its path seemed crooked. Its gelatinous form jiggled. "Hic!" it said. As if in response, the flivver vibrated. Grampa looked querulously toward the airlock. "Flivver shouldn't shake like that. Not with the polarizer turned on." "Then what makes this planet so heavy?" Reba asked. "Then we've wasted another week on a worthless rock," Joyce complained. rich. We were going to find radioactives and retire to Earth like "This planet. It's not big, but it's fertile and it's harmless. As end of our search. Short of a miracle, we'll spend the rest of our lives right here—involuntary colonists." Joyce spun on him. "You're joking!" she screeched. "I wish I were," Junior said. "But the polarizer won't work. Either it's broken or there's something about the gravity around here that just won't polarize." spaceship rested on its improbable stern. The sixteen Earth hours that we get back to Earth," he amended. "You can't be Four's father. All over the Universe, gravity is the same, and if it's gravity, the "That's just supposition," Junior said stubbornly. "The fact is, it isn't because it doesn't. Q.E.D." of polarization itself. For some reason, it doesn't work here. Why? what's the theory behind polarization?" worry over 'why.'" perpetual-motion machines and those crazy longevity schemes when any "Well, no," Grampa admitted. "Actually I was just fiddling around with some coils when one of them took off. Went right through the ceiling, dragging a battery behind it. I guess it's still going. Ought to be out near the Horsehead Nebula by now. Luckily, I remembered how I'd wound "We're stuck," Reba said softly. "We might as well admit it. All we can we won't have to stop with one child. We can have all the babies we "You know the law: one child per couple," Joyce reminded her frigidly. "You can condemn yourself to exile from civilization if you wish. Not "Not now," said Four. "It shifts." "Fweep?" Junior repeated stupidly. "Fweep?" Fweep said eagerly. "He's why the flivver won't work. What Grampa invented was a linear polarizer. Fweep is a circular polarizer. He's what makes this planet so heavy. He's why we can't leave." skin—is more efficient in stopping particle emissions than several something with him. It's preposterous that we should be detained here at the whim of a mere blob!" "I don't figure it's a whim," Grampa said. "Circular gravity is what flivver won't move." "I don't care why that thing does it," Joyce said icily. "I want it stopped, and the sooner the better. If it won't turn the gravity off, we'll just have to do away with it." "How?" asked Four. "Fweep's skin is pretty close to impervious and you can't shoot him, stab him or poison him. He doesn't breathe, so "We'd have a long wait," Four observed. "Fweep is the only one of his "Probably he's immortal." "And he doesn't reproduce?" Reba asked sympathetically. "Probably not. If he doesn't die, there's no point in reproduction. Reproduction is nature's way of providing racial immortality to mortal "But he must have some way of reproduction," Reba argued. "An egg or water, which a planet this size ordinarily would have lost by now." Fweep for every planet and sun, big and little, polarizing the gravity "What I can't understand," Junior said thoughtfully, "is why the polarizer worked for a little while when we landed—long enough to keep us from being squashed—and then quit." "Fweep didn't recognize it immediately, didn't know what it was or "Well? What did it say?" "He said he didn't want his friend to leave him." At the word, Fweep rolled swiftly across the floor and bounced into problem. We can just leave Four here with Fweep." won't work." it would only say that the logical answer is the one I sug—" "Mother!" Junior warned. "We decided not to talk about it any more. It's out of the question. If that's the only way we can leave this planet, we'll stay here until Four has a beard as white as Grampa's!" it's the cannibals and the missionaries. We can't leave Fweepland because because he doesn't like gravity that's polarized in a straight line, and he don't want Four to leave him.

<question>:
What is the ultimate reason that the family can’t leave the planet?

<options>:
A Four’s companionship with the blob creature
B The polarizer is missing parts
C They are out of fuel
D The crash landing damaged the fliverr

<answer>:

A