I need help with this chemistry question?

Question

Which of the following is evidence for a chemical reaction?

a. a gas is detected

b. a precipitate is formed

c. a color change is observed

d. an energy change is noted

e. all of the above

Answer 1

It's "e", all of the above.

Answer 2

I think it's e.

Answer 3

All of them.

Answer 4

A or E

Answer 5

The answer is e. all of the above.