Question

10 at first, the policy seemed harmless, but over time its ______ effects began to undermine trust and morale within the group. a uniformity b insidious c defiant d irrefutable

Explanation:

The sentence contrasts the policy's initial harmless appearance with its later harmful, gradual impact on trust and morale. "Insidious" describes something that develops gradually and subtly but causes harm, which matches the context. The other options do not fit: "uniformity" refers to consistency, "defiant" means resisting authority, and "irrefutable" means impossible to disprove.

Answer:

B. insidious