Final answer:
Endocrine signals are slower than paracrine signals due to the need for hormonal diffusion through the bloodstream, resulting in a lengthier travel time and dilution effect.
Step-by-step explanation:
Endocrine signals are transmitted more slowly than paracrine signals because they require diffusion through the bloodstream. Unlike paracrine signals, which act locally and elicit quick responses, endocrine signals must travel long distances and are subjected to dilution, leading to lower concentrations when they reach their target cells. The correct answer to the multiple-choice question is c) They require diffusion through the bloodstream.