Answer:
What stops Benvolio from approaching Romeo is that he noticed that Romeo purposely hides from him when they meet walking. The correct answer is the last one.
Step-by-step explanation:
We can find the answer to this question in the excerpt from act I, scene I of Romeo and Juliet: "So early walking did i see your son: towards him I made; but he was ware of me, 110 and stole into the covert of the wood: i, measuring his affections by my own, that most are busied when they’re most alone, pursu’d my humour not pursuing his, and gladly shunn’d who gladly fled from me." Specially in the line that says "did i see your son: towards him I made; but he was ware of me, 110 and stole into the covert of the wood", by reading this, it is very clear that Benvolio want to approach Romeo, but he sees how Romeo hides from him when he sees Benvolio and he regrets to do it.