Question: why do we say we dont want to quotruinquot a...

Why do we say we don't want to "ruin" a friendship by making it sexual? (book: the gendered society by Michael Kimmel 6th edition)

a) When a friendship becomes sexual we feel like we "own" that person

b) Making a friendship sexual brings on jealousy and damages other friendships

c) When a friendship turns sexual, we become more self-conscious around that person

d) When a friendship turns sexual, we lower the ranking of that person from "friend" to "lover"