Looking back over an 80-year lifespan, a typical person in a wealthy country have seen his or her annual income quadruple. But looking from one year to the next, the improvements in living standards that come from higher incomes are glacial.
(A) have seen his or her annual income quadruple. But looking from
(B) would have seen his or her annual income quadruple. But looking from
(C) would have seen his or her annual income quadruple, but if we are looking from
(D) have seen his or her annual income quadruple, but if we are looking from
(E) would have seen his or her annual income has grown four times. But looking from
First Vertical split b/w have seen vs would have seen
Whenever there is some level of uncertainty involved always prefer using would
A and D eliminated
In C , but if we are looking not correct
In E annual income has grown four times.is no better than quadruple
So A is the best answer