i like D.

A. explains why prices havent risen farther, not why import sales have remained high despite high prices

B. cost of manufacturing may have been less abroad, but the fact remains that prices of imports have risen in recent years. doesnt explain why import sales havent fallen.

C. coming shortage is expected to decrease future sales, doesnt explain why current sales have been high despite high prices

D. high prices mean high quality, explains why consumers might be motivated to go for high quality more expensive products.

E. talks of US made products. out of scope.

It’s already given that the price of imported items is greater than that of the items manufactured in the US. Hence, A and B are ruled out; manufacturing cost might be less but after import the price is higher. Also, the options doesn’t give any reason for still high sale of imported items. C is talking about future – ruled out. Irrespective of what US manufacture did to attract the customers, the fact is imported items are in demand. E doesn’t give any justification – ruled out. Left with D. The option give a reason of high sale: people think the quality of imported goods has improved and the price is justifiable.

A - Doesnt matter, prices are still high so no justification
B - Cost? Doesnt matter to consumers
C - Future plans, doesnt explain the present confusion
D - Good point, people still want to buy cos the cost is justified
E - Out of scope

IMO D

I am leaning more towards D, but I'm not sure about it.