Both C and D are the same so either could be correct, but it is not a or b that’s for sure
"Megan Parker keeps running to check her mailbox, she is waiting for a letter from my cousin."
Correct version
"Megan Parker keeps running to check her mailbox. She is waiting for a letter from her cousin."
Answer: jurist pint
Explanation: if I’m being honest I need points so I’m answering your questions truthfully
It is a strategy used before and during reading; Previewing a text helps the reader to develop the main subject and prepare his mind to receive the informations from written materials.