The two ways of relating what a person has said are 1)direct and 2)indirect (reported).
In direct speech, the exact words of the original speaker are repeated.
In the indirect speech (reported speech), the exact meaning of what the speaker told is expressed but not necessarily in the speaker’s exact words.
As per the rule, when any sentence is rewritten in indirect speech, can is converted to could. And the first person changes to the third person as per the subject. 'I' changes to 'he' and 'you' changes to 'him'. Therefore option C is the correct answer.
