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:
answer is A hope this helps
Explanation:
The answer is D. Pity
Cathy’s love for Linton is just pity. Cathy is physically attracted to Hareton and it quite obvious that Hareton has the same feelings towards Cathy. Hareton even tries to become better as a person and has even become jealous of Linton.