Choice D is the best answer because the simple present tense verb “watches” is consistent with the tense of the verbs in the rest of the sentence and paragraph.

Choice A is not the best answer because “watched” creates an inappropriate shift to the past tense.

Choice B is not the best answer because “had watched” creates an inappropriate shift to the past perfect tense.

Choice C is not the best answer because “would watch” creates an inappropriate shift that suggests a habitual aspect (other verbs in the sentence and paragraph, however, indicate that a specific instance is being narrated).