The correct answer is: D. is/is looking
The sentence is in the present tense, so the verb “to be” should be in the present tense as well. The man is currently sitting at the table, so the verb “to look” should also be in the present tense.
Option A is incorrect because the verb “to be” is in the past tense. The man is currently sitting at the table, so the verb “to be” should be in the present tense.
Option B is incorrect because the verb “to be” is in the past tense and the verb “to look” is in the past participle form. The man is currently sitting at the table, so the verb “to look” should be in the present tense.
Option C is incorrect because the verb “to be” is in the past tense and the verb “to look” is in the past tense. The man is currently sitting at the table, so the verb “to look” should be in the present tense.
I hope this helps!