The word "convergence (in Para. 3) means__________.

A．Deaf children are born to tie gestures with meanings.
B．Gestures used by the deaf and the normal are similar.
C．No countries share similar gestures orders in sign language.
D．NSL is to some extent similar to spoken language.

A．a non-verbal language created by deaf children.
B．an artificial language used by people in Nicaragua.
C．a language invented by teachers who teach the deaf.
D．a language described and modified by deliberate linguists