Answer:
The correct option is 15 seconds.
Step-by-step explanation:
At the time of exercise, our muscles contract rapidly. The contraction of the muscles is a phenomenon which occurs from the energy source ATP.
There are four sources of obtaining ATP at the time of muscle contraction. One of this source is phosphocreatine.
The phosphocreatine can create ATP for 15 seconds after the muscles start to contract. Phosphocreatine has the ability to donate a phosphate group to ADP to produce ATP.