Answer:
The sentence that corrects the pronoun errors is D. If people want to help their community, they should research opportunities.
Step-by-step explanation:
A pronoun is a word used to stand for a noun. To avoid confussion, pronouns must refer clearly to one unmistakable noun and agree with it. In this sentence, there are two pronouns: their -possessive- and they -personal-, and they are both correctly referring to the noun people.