Respuesta :
They will see.
"They" and "he" are third person, but only "they" is third person plural. The verbs "will have been seen" and "will be seen" are not correct because being seen is not the same as seeing. The verb "will have seen" is not in the future tense, but in the past tense. The verb "sees" is also not in future tense because it is a current action. The verb "will see" is the only verb that is in future tense and describes seeing something. Hope this makes sense.
"They" and "he" are third person, but only "they" is third person plural. The verbs "will have been seen" and "will be seen" are not correct because being seen is not the same as seeing. The verb "will have seen" is not in the future tense, but in the past tense. The verb "sees" is also not in future tense because it is a current action. The verb "will see" is the only verb that is in future tense and describes seeing something. Hope this makes sense.