The correct answer is D) steep mountains.
There is little farmland on the southern Pacific coast because of the steep mountains.
We are talking about the region of California, Oregon, and Washington. In this region, we can find three major mountain ranges that make agriculture, difficult. These mountain chains are the Peninsular Ranges, the Transverse Ranges, and the Klamath Mountains. These include the region of mountains such as the Diablo Hill, Sierra de Salinas, and the Sierra Madre Mountains.
The other options of the question were A) arid climate. B) limestone sinkholes. C) industrial pollution.