The correct option is A NO CHANGE
Some verbs take two objects, a direct object and an indirect object. For
example, in the sentence 'Shaima gave a pen', there is only one object
'pen'. In the sentence 'Shaima gave me a pen', (or 'Shaima gave a pen to
me) there are two objects, 'me' and 'pen', where 'pen' is the direct object
and 'me' is the indirect object. The indirect object is the recipient of the direct object.
In the given sentence, "some presents" is the direct recipient of the action "sent" and "us" is the recipient of "some presents", hence it is the indirect object. The sentence does not need any change as the indirect object is underlined, so A is correct. "They" is the subject and "sent" is the verb, hence options B and C are incorrect. "Some presents" is the direct recipient of the action "sent", hence option D is incorrect.
Note: The direct object answers the question 'what?' and the indirect object answers the question 'to who/whom?'