[求助]再問OG10th-019

#19

In addition to having more protein than wheat does, the protein in rice is higher quality than that in wheat,

 with more of the amino acids essential to the human diet.

(A)the protein in rice is higher quality than that in

(B)rice has protein of higher quality than that in

(C)the protein in rice is higher in quality than it is in 

(D)rice protein is hgher in quality than it is in

(E)rice has a protein hegher in quality than

正確答案是(B)

想請問各位NN,為何(B)正確阿?

than不是連接詞嗎?為何後面沒有主詞動詞呢?

(E)又錯在哪呢?

謝謝! 

為何