Question

which of these pairings is incorrect?
○ blood cells, components of blood
○ neurons, conduct electrical impulses
○ epithelial cells, react to stimuli
○ muscle cells, elongated cells that can contract

Explanation:

Blood cells are components of blood. Neurons conduct electrical impulses. Muscle cells are elongated and can contract. Epithelial cells mainly function in protection, secretion, absorption etc., not in reacting to stimuli (it's mainly the function of nerve - related cells like neurons).

Answer:

epithelial cells, react to stimuli