When first to the market the computer software was not a success due to its complexity

问题补充：

When first to the market, the computer software was not a success due to its complexity in operation.

A. introducing

B. being introduced

C. introduced

D. to be introduced

答案：

A. introducing

B. being introduced

(答案→)C. introduced

D. to be introduced

解析：本题考查非谓语动词。句中逻辑主语为the computer software，与introduce的关系为被动关系，故用过去分词，选C。