B is the correct answer since acid corrode on metals such as carbon, steel, zinc and such.
Time taken by the water balloon to reach the bottom will be given as

here we know that


now by the above formula



now in the same time interval we can say the distance moved by it will be


so it will fall at a distance 15.7 m from its initial position
I think it because of UV rays ultra violet ray which can make their colors different
Differentiation in its simplest of terms means breaking something into small parts. On the other hand, integration is taking those really small parts and gluing them in the right order. In short, these terms are the direct opposite or inverses of each other. The term which can tell you how fast you are going at a moment in time at ones current location is called a derivative. The term on the other hand, which can tell you how far you have travelled if you have been keeping track of your location and your time is what an integral is referred to. It is like differentiation only needs knowledge on the local neighbourhood while integration will need the knowledge on a global knowledge.
I think that the answer to that is true hope that helps