Atp is called the energy currency of the cell because
a glucose is made of atp
b atp catalyzes all metabolic reactions.
c atp allows one organelle to be exchanged for another
d most of the energy that drives metabolism is supplied by atp

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.