When blood glucose concentration rises, the pancreas secretes , and when blood glucose levels fall the pancreas secretes .

Explanation:

when glucose concentration is high the pancreas secretes more insulin while if the glucose level falls the pancreas secretes glucagon to raise them

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.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added