The correct singular, third person, conjugation of the verb to be in the future perfect tense is B. She will have been. In the other sentences, 'they' belongs to plural, third person; 'you' belongs to singular, second person and 'I' belongs to singular, first person.
<em>The future perfect tense</em> refers to the action that will have been done or completed in the future at some point. It is often used with timely expression.
Formation of the future perfect tense is as follow,
Subject + will have/shall have + past participle of verb (3rd form) + object.
For example:
She will have been here for four months during summer vacations.
She will have been done with her exams before Christmas.
Steady Eddie, The Thug, Dirty Deed, Doo-Doo Bug and Mr. Jimmy - These are the band members who tease Bud unmercifully, but also show him how to be a good and loving person.
