Final answer:
The past tense 'held' is the correct verb to use when completing the sentence about handling a friend's baby carefully.
Step-by-step explanation:
The correct option to complete the sentence 'I went to visit my friend and ______ her baby very carefully because she was a tiny baby' is option 4) held. The sentence is talking about an action that happened in the past, therefore, the past tense of the verb 'hold' should be used, which is 'held'. The correct formation of the sentence is 'I went to visit my friend and held her baby very carefully because she was a tiny baby.'