What form of pulcher agrees with magistris? pulchrae pulchris pulchro pulcher?

Ther are many reasons.. is it a multiple choice?

Give me the statements

In some developing nations the percentage of the animal protein from fish in the diet can be as high as 25 percent.  about 85% of fish caught is used for human consumption.  the remainder is converted into fishmeal and fish oil. 

Your answer is a because that is true