Which one uses the correct verb form?

a. if my brother were here, he could explain how to make the computer program work.
b. if my brother was here, he could explain how to make the computer program work.

What are the effects of parallel structure in this excerpt? check all that apply. it adds emphasis to the verbs that describe the british government’s oppression. it uses repetition to add power to the colonists’ growing list of grievances. it stresses jefferson’s list of grievances, giving the reader a sense of the amount of time the colonists have been oppressed. it emphasizes that all of these acts were carried out by the same person.