It is with the help of Tom ______our team has completed the project ahead of time.

选择一项：
a. which
b. what
c. that 解析：译文：正是在汤姆的帮助下，我们队提前完成了项目。本题考查强调句的用法。强调句结构为： It is / was ＋强调部分＋ that ……，根据句子意思及其结构，故选 C。
d. when