Confused about mark scheme: thermal/flow rate question

Hi, confused about this marked multiple choice question. I understand the SHC equation, I understand flow rate=m/t and the rearrangement. The bit I’m confused about it that power is equated to charge over time? I’ve never seen that relationship before and I googled it and couldn’t find anywhere that suggested that P=q/t. Im really confused. Is this mark scheme correct? I thought power was work done over time.
Sorry if this is a silly question, I’m just thrown off.