rationale

经理向我们解释了裁员决定的理由。

The manager explained the ___rationale behind the layoff decision to us.

老师在班上解释了考试改革的理由。

The teacher explained the ___rationale for the exam reform to the class.

老师向我们解释了课程调整背后的理由。

The teacher explained the ___rationale behind the curriculum adjustments.