Final answer:
Creatine phosphate is synthesized from glycine and arginine. It serves as an energy reserve for generating ATP in skeletal muscle. Option A is the correct answer.
Step-by-step explanation:
Creatine phosphate is synthesized from the amino acids glycine and arginine. In skeletal muscle, excess ATP transfers its energy to creatine, producing ADP and creatine phosphate. This compound serves as an energy reserve that can be quickly utilized to generate ATP during muscle contraction.