After the new technology was introduced,the factory produced

选择C是正确的.
请参考表示倍数的比较级用法：
1、 A is …times the size /height/length/width of B.
The new building is three times the height of the old one.
这座新楼比那座旧楼高三倍.(新楼是旧楼的四倍高)
2、 A is …times as big /high/long/wide/large as B.
Asia is four times as large as Europe.
亚洲是欧洲的四倍大.(亚洲比欧洲大三倍)
3、 A is …times larger /higher/longer/wider than B.
Our school is twice bigger than yours.
我们学校比你们学校大两倍.
根据上面的第二种用法,可知：如果A是B的两倍那么多就用：
A is twice as many as B.
所以本题选择C.

C
twice as many