Option A: INCORRECT
This is just a direct message with no lexical analysis whatsoever,lacking in meaningful description, it is under-specified.

Option B: INCORRECT
This option would have easily be correct if not for the use of the singular modal auxiliary verb ''has'' in a plural environment. Should at least have the plural ''have''.

Option C; INCORRECT
The numbers of mobile users ''have'' grown. have here, means there's a nexus, concord, a connection between the active participating words in the statement. The resulting ''have'' plural form, must however be in supporting condition and not as a subject here.

Option D: INCORRECT
This statement is grammatically incorrect. It is lacking in agreement with the other active subject elements in the body of the writer's opinion.

Option E; CORRECT
This is an apt sentence with not-too-lengthy words, not-too-ambiguous ones and easily comprehensible. The ''number'' here is an intangible noun which shouldn't be combined with another intangible noun ''users'' which would render the statement over-specified.