Answer:
None, really.
but if one of them has to be right, then it is D)
Step-by-step explanation:
A) the Earth is NOT flat, which anybody can verify and prove by e.g. getting on a high object (skyscraper, mountain, flying in an airplane, in a hot-air balloon, ...) and compare how much farther he/she can see compared to standing on the ground. or by watching a sailboat leaving the shore, and then the body disappears under the horizon, and more and more the masts go under too. but then it comes back or nears another shore, and the opposite happens (it did NOT fall off the disk ...).
B) water boils at 100° Celsius (centigrade). not Fahrenheit.
C) Oxygen is the very opposite of a noble gas. it combines easily with many other elements (many such combinations happen even so fast that we can see them as fire or explosions).
a noble gas (hence the name) is very, very reluctant to combine with anything. it is almost impossible, and it requires huge efforts to get at least some reactions.
D) Gravity is in its essence an attractive force (therefore the apple is falling down from the tree, as Earth and apple attract each other).
but it has been shown that under certain circumstances (a system with varying gravitational mass) it can have a repulsive behavior too.