Answer :
Well,
Obviously, this is a sentence involving the present perfect tense.
Option A is in present tense.
Option C is plural and it is present tense.
Option D is in past tense.
Option B is the only option left.
Obviously, this is a sentence involving the present perfect tense.
Option A is in present tense.
Option C is plural and it is present tense.
Option D is in past tense.
Option B is the only option left.