Answer:
The answer is A
Explanation:
An illustration is the way that question can be answered as it requires a visual approach.
Given the excerpt above, it's hard to tell the boom's shape just by using text.
Option B already has the answer there which is between 70-90feet.
Option C has been answered in this line "...so that both move together when the derrick swings to a new direction"
Option D has been answered that it's attached at the base of the mast.
Therefore the answer is option A.
