Which of the following is a chemical change

I'm guessing the answer choices are:

A. ice melting

B. ice being carved

C. water boiling

D. water breaking down into hydrogen and oxygen

The answer, if any of these choices, would be C

1 a

2 b

3 b

4 d

5 d

6 d

explanation:

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.