There are two new words in conclusion -> Low cost , Same nourishment => we need to attack

The country of Ertland has never imported apples in any significant quantity because consumers there generally prefer the unique texture of Ertland-grown apples. Nevertheless, apple growers from Kosolia, a neighboring country, plan to sell their apples in Ertland by selling Kosolia-grown apples at half the price of local apples and promoting them as a nourishing, low-cost alternative.

Which of the following, if true, casts most doubt on the viability of the plan by Kosolia's apple growers to sell their apples in Ertland?

A Most of the varieties of apples grown in Ertland were originally derived from common Kosolian varieties.
wrong- it actually strengthens...the varieties are same

B Consumers in Ertland tend to spend about the same proportion of their income on fresh fruits and vegetables as do consumers in Kosolia.
wrong- Does not attack the conclusion
C At times in the past, Ertland has exported significant quantities of apples to Kosolia.
wrong- not related to conclusion
D Some varieties of apples grown in Kosolia can be harvested throughout most of the year, whereas the varieties grown in Ertland can be harvested only during two months of the year.
wrong- it does not attack the low cost
E Profit of Ertland-grown apples are high enough in Ertland that growers, wholesalers, and retailers there could easily afford to reduce the price at which these apples are sold.
Correct - perfectly attacks the low cost word in conclusion