B is your answer because secondary sources are generally scholarly books and articles
C: Who has the greatest need?
Answer: They didn't really have the resources and the equipment and they needed more time to decide if they were up to having their nation in danger.
Explanation:
Here’s the answer :
Following a failed invasion of Iraq in 686, Abd al-Malik focused on securing Syria before making further attempts to conquer the greater part of the Caliphate from his principal rival, the Mecca-based caliph Abd Allah ibn al-Zubayr.