Anna is experiencing a restricted field of vision. another term for this is

The term is tunnel vision, restricted field of vision. A restricted field of vision less than 20 degrees wide. The ratio measurement of vision describes visual acuity, or the sharpness of vision, at 20 feet from an object, it is also describe the clarity of the vision. 

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.