Question

simple diffusion is best described as substances ________. answer moving actively against a concentration gradient moving actively down a concentration gradient moving passively down a concentration gradient moving passively against a concentration gradient i dont know yet

Explanation:

Simple diffusion is a passive transport process where substances move from an area of higher concentration to an area of lower concentration (down the concentration gradient) without the use of energy (passively). Active transport requires energy and moves against the gradient, so options with "actively" or "against" are incorrect.

Answer:

C. moving passively down a concentration gradient