ANSWER
B) 299 sections with 19 feet left over
Step-by-step explanation
To find the number of sections we have to divide the length of the rope by the length of each section:
The whole part of this result is the number of 21-foot sections we'll have. If we multiply the decimal part by 21 we can find the length of the rope left:
We have 19 feet left of the rope after cutting 299 21-foot long sections