Language is a complex adaptation shaped gradually by selection

Correct: B — Is best explained as a complex adaptation shaped by gradual natural selection for communication

Pinker & Bloom (1990) argued against then-popular views — including some influential statements by Chomsky — that the language faculty is a non-adaptive byproduct of brain growth or a single saltational change. They marshalled evidence that language exhibits the hallmarks of complex adaptation: many specialized parts (phonology, morphology, syntax) coordinated for a specific function (communication), shaped by gradient selection pressures. The paper helped legitimize evolutionary psycholinguistics and reframed the language-evolution debate; subsequent decades of work on FOXP2, vocal-learning circuitry, and comparative cognition have largely vindicated the broad framing while sharpening which specific traits are uniquely human.