Directions: In the sentence, certain words are in bold and numbered from A to H, which are the possible pairs to be interchanged. Choose the pair(s) of the words that need(s) to be interchanged to make the sentence grammatically correct and meaningful.

a. I respect a man who is effective(A) and follows through(B) - as long as he confines(C) it to his trials(D) household.
b. Preliminary results(E) show that the vaccine is decisive(F), but this has to be confirmed(G) by further medical own(H).