She met her friends in the lobby, the bottom floor, of the hotel so that they could head over to the refreshing pool for a cool, brisk swim. Which is the best revision of this sentence?
A.She met her friends in the lobby of the hotel, and they headed over to the pool for a cool, refreshing swim.
B.She met her friends at the hotel’s bottom floor, which is the lobby, so that they could head over to the swimming pool for a cool, brisk swim.
C.For a cool, brisk, refreshing swim at the hotel’s pool, she met her friends in the hotel’s lobby on the bottom floor.
D.The sentence is correct as written.

The answer to your question would be that the best revision of the sentence is the following one: For a cool, brisk, refreshing swim at the hotel's pool, she met her friends in the hotel's lobby on the bottom floor.

Explanation:

This is the best revision for the original sentence because it includes all the information. The sentence is not correct as written as it is very choppy and wrongly punctuated, so D is incorrect. As regards A, it can be said that it does not include the location of the lobby, that is, the NP the bottom floor. B, on the other hand, includes this information in a nonessential relative clause (which is the lobby) so it does not give this location the same importance as in the original. As the clause is nonessential, it is understood that it can be removed from the original sentence. Finally, C includes an introductory phrase for the information regarding the pool (for a cool, birsk, refreshing swim) and adds a preposition which takes the NP the bottom floor as complement.