What do these two changes have in common? snails growing shells rust forming on a bicycle frame Select all that apply.
A. Both are only physical changes.
B. Both are caused by heating.
C. Both are chemical changes.
D. Both are caused by cooling

Im not completely sure about the answer, but A and C are Wrong

Explanation:

This is because the snail growing its shell is a physical change. For the shell of a snail to grow, the snail must consume Calcium to grow its shell. And would grow it just like how we grow our fingernails!

Rust forming on a bicycle frame is an example of a chemical change. This is caused by metal being exposed to oxygen. Just like when you leave your bike outside in the rain, it'll get rusty!