It is I ____ against the plan, because it sounds impossible to carry out.

A. who are B. that are C. that is D. who am

D

句意“正是我反对这个计划，因为它听起来不可能实施”。本题考查强调句，根据It is ... that/who可知，去掉It is ____ that/who后，成分完整，剩下I ____ against the plan，用am，故选D。