The best option is:
a. The meanings of tete-a-tete in French and vis-a-vis in Latin were similar, but the English meaning of tete-a-tete has not changed much from the French, while vis-a-vis has taken on a different meaning in English.
This option correctly identifies that the literal meanings of both terms were related (tete-a-tete meaning "head-to-head" and vis-a-vis meaning "face-to-face") but highlights that tete-a-tete has retained a meaning more aligned with its French origins, while vis-a-vis has shifted to a different meaning in English related to comparison or relation.