What do the words answer to this most likely mean It is plain they would answer to this that you have come from the country and from very far in the country?

Answer 1

This is an excerpt from the Jungle by Upton Sinclair, Jr:

Jurgis was like a boy, a boy from the country. He was the sort of man the bosses like to get hold of, the sort they make it a grievance they cannot get hold of. When he was told to go to a certain place, he would go there on the run. When he had nothing to do for the moment, he would stand round fidgeting, dancing, with the overflow of energy that was in him. If he were working in a line of men, the line always moved too slowly for him, and you could pick him out by his impatience and restlessness. That was why he had been picked out on one important occasion; for Jurgis had stood outside of Brown and Company's "Central Time Station" not more than half an hour, the second day of his arrival in Chicago, before he had been beckoned by one of the bosses. Of this he was very proud, and it made him more disposed than ever to laugh at the pessimists. In vain would they all tell him that there were men in that crowd from which he had been chosen who had stood there a month--yes, many months--and not been chosen yet. "Yes," he would say, "but what sort of men? Broken-down tramps and good-for-nothings, fellows who have spent all their money drinking, and want to get more for it. Do you want me to believe that with these arms"--and he would clench his fists and hold them up in the air, so that you might see the rolling muscles--that with these arms people will ever let me starve?"

"It is plain," they would answer to this, "that you have come from the country, and from very far in the country." And this was the fact, for Jurgis had never seen a city, and scarcely even a fair-sized town, until he had set out to make his fortune in the world and earn his right to Ona.

The portion 'they would answer to this' means the older men were responsing to Jurgis' long self-congratulatory statements. The author could have written, "It is plain," the men said, "that you have come...." and it would have the same meaning.

Answer 2

The phrase "answer to this" likely means to respond or acknowledge a certain question or statement. In this context, it suggests that it is obvious or clear that the individual being referred to has come from a rural area or a distant location within the rural countryside.