The synonym of glib would be insincere...
if you look up the definition in the dictionary it tells you that glib refers to someone that is insincere
hope this helps :)
The correct answer of the given question above would be option C. The excerpt from the story "Marriage is a Private Affair" that reveals cultural differences that contribute to the dilemma is "the boy’s mind is diseased, and only a good herbalist can bring him back . . . .”
