The committee insisted that the proposal ______ without delay.
be discussed
to be discussed
is discussed
is to be discussed
句意：委员会坚持要求立刻讨论这个提议。在insist. order， command, demand, desire, require, request 等词后的宾语从句要用虚拟语气。这类虚拟语气由"should+动词原形”构成,其中should通常可以省略。故选A。