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

<passage>:
with soft white-and-brown material. Emblems on plastic wrappers embedded in material identify it incontrovertibly as an undetermined —and mankind had to eat crow! guaranteed weather-controlled future summer day dawned on the Mississippi Valley, the walking mills of Puffy Products Ukrainian crisis, the government ("Spike to Loaf in One stopped sales and deliveries of all As they advanced, their heads swung lazily from side to side, very much like snakes, gobbling the yellow grain. In their throats, it was threshed, the chaff bundled and burped aside for pickup by the crawl trucks of a chemical corporation, the kernels quick-dried and blown along into the mighty chests of the machines. There the you know that?" Roger countered feebly. "Yes, I substituted hydrogen. The metal-foil wrapping would have added just enough weight to counteract the greater buoyancy of the hydrogen loaf. But—" "So, when this morning's loaves was clipped into loaves and shot wrapper, or reach for the sky if they happened to unwrap the stuff matter of seconds, a fierce heat-front browning the crusts, and the piping-hot loaves sealed in transparent outdoors?" plastic bearing the proud Puffyloaf emblem (two cherubs circling a floating loaf) and ejected onto the delivery platform at each serpent's rear end, where a cluster piglets, snatched at the loaves A few loaves would be hurried and he testified that he always molded his first attempts from Puffybread, one jumbo loaf squeezing of a peanut." HER photocells dimmed and loaves began to appear on the down to approximately the size The loaf's unwrapped. After a while, in spite of the crust-seal, a mixture. Housewife in curlers and kimono pops a couple slices in the toaster. Boom!" The three human beings in the across the hot rippling fields. THE robot claws of the pickup was snagged by a thrusting flight of loaves approached. The our flying loaves rising high." trifle late in the day. If the mills are still walking and grinding, approximately seven billion Puffyloaves eight and one-half loaves per person when a sub-flight of the loaves, wind or lacking the natural buoyancy of the rest, came coasting silently as the sunbeams between the Army: Why do loaves flame when the upper lids, and his head burrowed beneath his forearms. Ukrainian kulak now that Moscow's brown and glistening bread-front in curiosity and dipped back in awe. loaves a wide berth, but some them furiously with beaks and claws. Hydrogen diffusing slowly through the crusts had now distended most of the sealed plastic wrappers into little balloons, which ruptured, when pierced, with disconcerting pops . the flying bread drew angry protests the Board eating out of my hand." "Hah! I guarantee you won't today!—you're going to see from conservationists and a flood in its treatment of the Ukrainians, bread as a farce perpetrated by bread booby-trapped by Capitalist "Miss Winterly, please—our theme." The Blonde Icicle's face thawed into a little-girl smile as she chanted bubblingly: " And reinforced with sturdy oats, It rises through the air and floats— The bread on which all Terra dotes! bread out of the air and enjoy a historic sandwich. Phineas T. Gryce, escaping from his own managerial suite, raged to trap the errant loaves. He was the inauguration of the helium-filled to shoot down the loaves as they loaf ('So Light It Almost Floats Away!') in which that inert and conference table, calm and clear-headed as ever. But the bread flight, swinging away from a hurricane moving up disappeared into a high Atlantic overcast, also thereby evading a local storm generated by the least disperse the H-loaves. by Communist and Capitalist governments sought lighter, whiter bread. Indeed, loaves floating down from the gray bran and wheat germ from the flour was an even more important advance. Early bleaching and preserving The bread flight, rising above an have destroyed it, passed unobserved across a foggy England and rose out of the overcast only over Mittel-europa. The loaves had at last reached their maximum altitude. The Sun's rays beat through the rarified air on the distended plastic wrappers, increasing still further the pressure of the confined hydrogen. They burst by the millions and tens of millions. A high-flying gave us away at the start with that of the event, afterward described it as "the foaming of a sea of diamonds, the crackle of God's knuckles." BY THE millions and tens of millions, the loaves coasted down into the starving Ukraine. the Ukraine. sadly. "Wait a sec. How about?— " There'll be bread black bread, recently aerated itself bread, was quietly destroyed. falls of loaves occurred, giving rise When you die— It's a lie! "I don't know why we chanted crooks at Fairy Bread." He scowled, turning back his attention to Tin had hurled them down, adjusted Philosopher. "I get whopping mad, brightened. "Oh, boy—hydrogen! a-smile, muttering terse comments and questions into the lapel mike in the dough and later killed by the heat of baking, their corpses remaining in situ of the worldwide publicity, Puffyloaves are outselling Fairy Bread Ukrainian crisis is over, has taken the ban off helium and will also sell us stockpiled wheat if we need it. We can have our walking mills loaves with the noble gas helium, an element which remains virginal in the face of all chemical temptations and whose slim molecules are helium loaf!" WITHOUT changing expression, Phineas T. Gryce rapped hydrogen loaf." "Good!" Roger cried. "We'll tether 'em on strings and sell 'em like balloons. No mother-child shopping team will leave the store without a cluster. Buying bread balloons will be the big event of the day for kiddies. It'll make the carry-home shopping load lighter too! I'll issue orders at once—" in horror. "Fairy Bread is outselling Puffyloaves by an infinity factor. So far this morning, sessile shops." "Mr. Snedden!" Gryce barked. "What bug in the new helium unless—just possibly—there's been some unforeseeable difficulty involving the new metal-foil wrappers." "Metal-foil wrappers? Were you responsible for those?" around him. "My sweet little ever-victorious, self-propelled monkey wrench!" she enough to cause drift during stackage. Drafts in stores might topple sales pyramids. Metal-foil wrappers, by their added weight, took care of the difficulty." of the new loaf might be great and—" "Why, you fool! I noticed that order for metal-foil wrappers, assumed it was some sub-secretary's mistake, and canceled it last night!" 'bread overhead' jingle. We've "You canceled it?" he quavered. "And told them to go back to the lighter plastic wrappers?" "Of course! Just what is behind all this, Mr. Snedden? can only arrange, say, a fur-famine struck another blow against the months ago that the helium loaf was safely stackable in light airs and gentle breezes—winds up to wrappers result in complete non-delivery?" ROGER Snedden's paleness became tinged with an interesting P.T. Gryce's frown grew blacker by the moment, while Megera Winterly's Venus-mask windshield found thinly plastered

<question>:
What caused the loaves to eventually fall on the Ukraine?

<options>:
A A storm generated by the weather service
B A Bulgarian evangelist who did so on accident
C Being shot down by Soviet planes
D The sun bursting the plastic wrappers

<answer>:

D