Changes listed in A, B and C are as follows :
A. Creating some objects with paper: When we create different objects like aeroplane, boat, bird, etc. by folding a sheet of paper, only shape and size changes. We can get back the original sheet by unfolding it again.
B. Playing with a balloon: When we loosen the grip of the inflated balloon we get the original shape of balloon back, and we can inflate it again but when we prick the inflated balloon with a pin, it gets deflated with a hole in it, so we cannot able to inflate it again.
C. Crushing a piece of chalk: When we crushed a piece of chalk to powder form, we cannot can get back the original piece of a chalk.