Antonym of GLIB

Answer: Option B

Glib : (of words or a speaker) fluent but insincere and shallow.
Unwilling : not ready, eager, or prepared to do something.
Dumb : temporarily unable or unwilling to speak.
Modest : unassuming in the estimation of one's abilities or achievements.
Halting : slow and hesitant, especially through lack of confidence; faltering.

Antonym of Glib is Dumb