Look at _____! He's really happy.
his
them
he
Him
In the test sentence ‘Look at ___! He's really happy.’ some personal object pronoun is omitted:Look at whom?. In the English language there are 7 personal object pronouns: me, you, him, her, it, us, and them.We use personal object pronouns after (1) verbs as the object of the verb (I love her, but she doesn't love me.; I saw her at the university yesterday.) and after (2) prepositions: He is talking to her about them.As the context is given in the test: ‘…He's really happy.’, it is evident that in the previous sentence ‘Look at ___!’ the speaker invites somebody to look at some male person. Therefore, the personal object pronoun that correlates with the personal subject pronoun ‘he’ is ‘him’: ‘he’ (the personal subject pronoun) → ‘him’ (the personal object pronoun).Therefore, we choose ANSWER 4: him.