The correct option is
D laugh
In order to fill in the blank with the most suitable verb, we need to understand the usage of 'make'. 'Make' means to force someone to do something. If 'make' is used in a passive (voice) sentence, we use the word 'to' along with the verb. In an active sentence, we do not use 'to' with the verb. The verbs without the marker 'to', are called bare infinitives.NOTE: Here, 'makes' is used to describe the action in present tense. 'Makes' is the third person form of the verb.
As the given sentence is in active voice, we will use the bare infinitive here.
Option B - As the main verb already describes the action of the third person in the third person form of the verb, we need the second verb to be in its original form. Hence, option B is incorrect.
Option C - 'Laughed' is the past form of the verb 'laugh'. As 'makes' is the main verb, we need the secondary verb in its original form. Hence, option C is incorrect.
Option D - The marker 'to' is used with the verb, when the sentence is in passive voice. As the given sentence is in active voice, we will use the verb in its original form without the marker 'to'. Hence, option D is incorrect.
Option A - 'Laugh' can be correctly used here, as it is a verb in its original form. Hence, option A is the correct answer.
'My sister often makes me laugh when I'm sad.'