试行新的技术之后,此区域的小麦产量是之前的三倍。
After adopting the new technology, wheat yield in this region is 3 times what it was before.
B. After adopting the new technology, wheat yield in this region is 3 time before.
C. After adopting the new technology, wheat yield in this region is 3 times that of before.
D. After adopting the new technology, wheat yield in this region has been tripled.