Which system transports nutrients to body cells? a. respiratory system b. muscular system c. skeletal system d. circulatory system.

currents is the correct answer.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.