What solution does Benvolio suggest to Romeo in Act 3, Scene 1?
Benvolio tells Romeo to follow his lead. Look at other ladies. There are other people than this Rosalind girl. Benvolio hopes that if Romeo sees that there are other girls that may return his affections that will forget Rosalind.
In the beginning of the play, Romeo is lovesick over Rosaline. Romeo ends up reading the Capulet guest list for the party and Romeo's friends including Mercutio and Benvolio decide to go. Benvolio encourages Romeo to look at other girls at the party and to forget Rosaline.
The solution Benvolio suggest to Romeo is to go away from Verona before the guards come and attack him.
Before in the story, the prince had already talked to Montague and Capulet three times so both Romeo and Benvolio were aware of the consequences that they were going to receive.