HELP! What is wrong with this sentence from the blue book?

<p>(A. Surely) one of the most far-reaching changes in the nineteenth century (B. will be) the change from working (C. at home)(D. to working in) the factory. (E. No error)</p>

<p>The given answer is B, but I don't know why! HELP ME! It seems obvious that it is wrong since the 19th century has already passed, which is why I almost put the right answer. But if this sentence were from a book written in 1780, would not the sentence be correct? </p>

<p>THANKS IN ADVANCE</p>

<p>If it was written in 1780, this sentence would be grammatically correct and also correct in context of the times. However, we live in the 20th century, so that warrants a past tense form of the verb. Tricky tricky.</p>

<p>To put it lightly, that's BS!!!!!! If that were on an actual test I'd taken, I would protest like there was no tomorrow. That happens to be the only writing question I missed on this whole test. Too bad my other scores are stuck in the sub-700 level.</p>

<p>We live in the 21st century.</p>