D. parallel structure just means that all of your verbs in the comma series line up in regards to tenses, here. in choice D, it's "BE friendly," "INTRODUCE yourself," and "SMILE." these are all present tense verbs.
the rest of the choices don't match--"exercise" and "stretching" are two different verb forms in choice A, "to go to the library" is the odd one out in choice B, ane "to build" doesn't match with the "-ing" verbs in choice C.
Answer: A
It may not follow a chronological order
Answer:
soon difficult because it's on laptop
Hi !!
It's a compound complex sentence
Although Mary isn't fond of reading makes it = complex (dependent clause)
she read Harper Lee's To Kill a Mockingbird, and she found it fascinating = compound (2 independent clauses)
hope I helped !
