avoid competition.
c.
cooperate with competition.
b.
attack competition.
Answer: People who assail competition (b.) attack competition.
Explanation:The word "assail" is a verb and it makes reference to the act of attacking something or critizing it strongly. Therefore, "assail" is a transitive verb and two of its synonyms are "attack" and "assault". Taking this into account, "people who assail competition" means "people who attack competition". In this sentence, "assail" is part of a relative clause which has been introduced by "who".