the pond water the watercress plants the minnows the crayfish
I gave my students this multiple choice question: A spring-fed stream forms a pond that contains watercress plants, minnows, and crayfish. The pond receives 5 hours of direct sunlight every day. Which of the following is an abiotic factor in this ecosystem?

Only one answer is correct among these 4 choices:
- the pond water
- the watercress plants
- the minnows
- the crayfish

Could you tell me which one is correct?

the pond water