Justify why the predator/prey relationship is a community level interaction

Predator/prey relationship is a type of relationship in the ecosystem that involves a prey that is eaten by a larger animal called the predator. This is an important community level interaction because this balances the population of the ecosystem. 

Explanation:

It is an interaction between two different species, so the organism, species and population levels are too low. The community level references interactions between members of different species.

Explanation:

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.