a-f In the given sentence the subject should be in the plural formfriends and the verb should be in the singular formwas. according to the Subject-Verb Agreement rule , One of Each of Most of Plural Subject Singular Verb is grammatically the correct structure. b-d The adjective recent is correct use in this context. Hence this sentence is correct. But it is incomplete. c-e Could is used to express possibility or past ability. Here in this sentence, the use of could is correct. hence option 5 is correct to - hence, option c is correct.