Prethinking: The income from wool sales adjusted against inflation increased sharply but the family still could not enjoy prosperity. Possible causes can be that the family had debts from previous business transactions that it had to pay, the family might had an unexpected issue such as accident or health problem to cope up with financially, the family might had lost more in other business than it gained from this business..
(A) At the end of the 1800s, prices in general in Australia rose more rapidly than did the wholesale price of wool sold domestically. The question stem mentions "income from wool sales (adjusted against inflation) increased dramatically". Hence, this option is
irrelevant. (B) The prices of wool sold to domestic markets by Australian sheep farmers decreased dramatically during the period in question.
Irrelevant. Amount of wool sold internationally increased dramatically and so did the income from wool sales.
(C) The international and domestic prices for mutton, sheepskins, and certain other products produced by all Australian sheep farmers fell sharply during the period in question. In line with prethinking, hold.
(D) Competition in wool sales increased during the period in question, leaving Australian wool producers in a less favorable position than previously. Even if the competition increased, the fact is given that the family's income from wool sales increased. Hence,
incorrect.(E) Among Australian sheep farmers, the percentage who made their living exclusively from international wool sales increased significantly during the period in question. The family clearly did not belong to this category.
Out of scope.Therefore, C.