Respuesta :
Answer:
A. Have you noticed how hard she works?
Explanation:
Every clause in the sentence seems to start as a independent clause, with an explicit subject (Anna) followed by a predicate. In order to vary this structure, an option that does not contain an explicit subject needs to be chosen - this is option A.
Option A does not mention Anna as the subject explicitly - unlike the other options. The subject is addressed as a singular second person (You).