Purebred cows native to Mongolia produce, on aver-
age, 400 liters of milk per year; if Mongolian cattle
are crossbred with European breeds, the crossbred
cows can produce, on average, 2,700 liters per year.
An international agency plans to increase the profita-
bility of Mongolia’s dairy sector by encouraging wide-
spread crossbreeding of native Mongolian cattle with
European breeds.

Which of the following, if true, casts the most serious
doubt on the viability of the agency’s plan?
(A) Not all European breeds of cattle can be success-
fully bred with native Mongolian cattle.
(B) Many young Mongolians now regard cattle raising
as a low-status occupation because it is less
lucrative than other endeavors open to them.
(C) Mongolia’s terrain is suitable for grazing native
herds but not for growing the fodder needed to
keep crossbred animals healthy.
(D) Cowhide and leather products, not milk, make
up the bulk of Mongolia’s animal product
exports to Europe.
(E) Many European breeds of cattle attain average
milk production levels exceeding 2,700 liters.

OA is C

Please explain.