these apples are very expensive.do you know ()?A how do they cost B how many do they cost

题目

these apples are very expensive.do you know ()?A how do they cost B how many do they cost
C how much do they cost Dhow much they cost为什么选D不选C?

答案

因为这里是作为know的宾语从句,要使用陈述语序