Ice melts into water. The correct equation to calculate the heat of this reaction is ...

O q=MCAT

O q=mAHV

O q=mAHE

O q=mc^2

q=mAHf

Explanation:

When water change form from solid (ice) to liquid, it will need heat that depends on the heat of fusion (Hfus). If the form changed from liquid to gas it will use the heat of vaporization (Hvap) instead. The heat of fusion usually written just AT

q=MCAT is used to calculate heat when temperature change (AT = delta T = difference in temperature)

q=mAHvap is wrong because you need if the form change from liquid to gas

q=mc^2 is wrong because it describes the relation of mass and energy, not the form.

The answer should be q=mAHf