Bilinguals exercise the same circuits that resolve conflict

Correct: B — Executive control tasks that require resolving conflict, such as the Simon and Stroop tasks

Bialystok et al. (2004) reported that older bilinguals outperformed matched monolinguals on Simon-task conflict trials, with the bilingual advantage growing with age. The proposed mechanism: managing two simultaneously active languages chronically exercises domain-general executive control, particularly inhibition of the irrelevant language. Subsequent meta-analyses have been mixed — vocabulary differences and study heterogeneity complicate the picture, and effect sizes vary across paradigms. The current consensus is that bilingualism reorganizes the language-control network in measurable ways, but a broad cognitive 'bilingual advantage' is more nuanced than the early reports suggested.