It was not until dark he found he thought was the correct way to solve the problem.
A. that; what
B. that; that
C. when; what
D. when; that
网友回答
(答案→)A. that; what
B. that; that
C. when; what
D. when; that
解析：这是—个带有宾语从句的强调句型。主句是not...until句型。该句型被强调时，只能强调not+until引导的状语。宾语从句是由关系代词what引导的。