The word "obscurity" in paragraph 2 could best be replaced by ______.

A．Words and phrases accepted by the majority for formal usage.
B．Words and phrases understood by the majority but not found in standard dictionaries.
C．Words and phrases that axe understood by a restricted group of speakers.
D．Words and phrases understood by a large number of speakers but not accepted as formal usage.

A．does not approve of either slang or colloquial speech in any situation
B．approves of colloquial speech in some situations, but not slang
C．approves of slang and colloquial speech in appropriate situations
D．does not approve of colloquial usage in writing