Which of the following contains an error in verb voice?

select one:
a. had i known you would be upset, i would have postponed the trip.
b. if she was a more active person, she would feel better.
c. i had hoped we would be further along than this by now.
d. if i were better in math, i would have done better in chemistry class.

The right answer is the B) If she was a more active person, she would feel better.

Explanation: Just to elaborate a little on the answer, it can be added that, with the exception of option C, these are examples of conditional sentences in English. There are various types of conditional sentences (zero, types 1, 2 and 3, and a mixed type) and most of them contain the word if. They are used to speculate about what could or might have happened, or about what we wish would happen.

Although it is not incorrect to say "if she was" in certain contexts, specifically when referring to probable or possible situations, it is incorrect to use it when referring to sutuations that are not true, or that you wish were true. Since the subject in this sentence IS NOT an active person, then "were" should be used instead.    

source text: from the sketch here given it will be seen, that our good grandmothers differed considerably in their ideas of a fine figure, from their scantily dressed descendants of the present day. a fine lady, in those times, waddled under more clothes even on a fair summer's day, than would have clad the whole bevy of a modern ball room. nor were they the less admired by the gentlemen in consequence thereof. on the contrary, the greatness of a lover's passion seemed to increase in proportion to the magnitude of its object—and a voluminous damsel, arrayed in a dozen of petticoats, was declared by a low-dutch sonnetteer of the province, to be radiant as a sunflower, and luxuriant as a full blown cabbage. certain it is, that in those days, the heart of a lover could not contain more than one lady at a time; whereas the heart of a modern gallant has often room enough to accommodate half a dozen - - the reason of which i conclude to be, either that the hearts of the gentlemen have grown larger, or the persons of the ladies smaller — this however is a question for physiologists to determine. add punctuation to the following excerpt. writing under the name of diedrich knickerbocker washington irving aimed his potent satire at as diverse topics as political rivals such as thomas jefferson to the very ideal of looking back on the past affectionately: a fine lady, in those times, waddled under more clothes even on a fair summer's day, than would have clad the whole bevy of a modern ball room. a voluminous damsel, arrayed in a dozen of petticoats, was declared by a low-dutch sonnetteer of the province, to be radiant as a sunflower, and luxuriant as a full blown cabbage. in those days, the heart of a lover could not contain more than one lady at a time; whereas the heart of a modern gallant has often room enough to accommodate half a dozen