OFFICIAL EXPLANATION

Malleable, pliant.


"Many sociologists" think "humans are $\qquad$ ," "but" a certain event leads the writer to conclude that "human nature is immutable," or unable to change. Therefore, the blank needs to mean changeable. "Monolithic" means large and indivisible and "homogenous" means uniform or unvaried, so neither of these matches the desired meaning. "Heterogeneous" and "variegated" (having a lot of variety) are tempting, but variety is not the same thing as change. The best choices are "malleable" and "pliant," which each mean physically bendable and, secondarily, easily influenced or changeable.