Answer:
The quotation that supports the idea that the Capulets and Montagues have been quarreling for some time is:
A. "By thee, old Capulet, and Montague, Have thrice disturbed the quiet of our streets"
Step-by-step explanation:
The quote above, spoken by Prince Escalus in Act I Scene I of "Romeo and Juliet", is a sign that the feud between the two families has been going on for some time now. The Prince is angry at the Capulets and the Montagues. Because of them, riots and confusion have taken place three times already. He threatens to punish them with death if they do not stop their quarrel so that peace can be maintained.