ticks feeding on a dog bees transporting pollen from flowers pilotfish swimming under sharks birds eating the insects from the back of a hippopotamus
I gave my students this multiple choice question: Which of the following symbiotic relationships is considered parasitic?

Only one answer is correct among these 4 choices:
- ticks feeding on a dog
- bees transporting pollen from flowers
- pilotfish swimming under sharks
- birds eating the insects from the back of a hippopotamus

Could you tell me which one is correct?

ticks feeding on a dog