Why Don't the Countries That Most Need High-Protein Crops Grow

Why don't the countries that most need high-protein crops grow them?

A) High-protein crops usually require fertilizers, which may not be affordable to these countries.
B) High-protein crops require extensive irrigation, which may not be affordable to these countries.
C) High-protein crops are more difficult to process, making the foods they produce too expensive.
D) High-protein crops are typically low in most other vital nutrients.