Answer:
C) Mountain biking is a popular, exciting sport and hobby for many biking enthusiasts.
Step-by-step explanation:
Standard English is a variety of the English language that is accepted as the usual correct form. As opposed to all the Nonstandard English dialects, it is widely used in formal settings, by the governments, the media, schools, and international communication. “Mountain biking is a popular, exciting sport and hobby for many biking enthusiasts” is an example of standard English because it contains words that can be used in formal settings and that can be understood by all English speakers (it does not have any slang or connotations).
The other sentences, on the other hand, are not examples of Standard English because “totally” is a slang used for emphasis, the meaning of the adjective “cool” is subjective and varies and change depending on the group who is using it, plus, it is very informal like “hang out.”