What is the best summary of the passage external and internal stimuli? A. An external stimulus comes from outside of the organism.
B. Stimuli trigger responses in organisms that allow them to maintain constant internal conditions through homeostasis.
C. Homeostasis in a set of mechanisms that work to maintain stable internal conditions as external conditions change.
D. Phototropism is a plants response to turn toward light. Gravitropism is a plants response to grow upward against gravity