Data Sufficiency

"At a certain department store counter each clerk will wrap no fewer than twenty and no more than thirty presents per hour.If seventy people are standing in line, will all of their presents be wrapped after one hour?"

1) Each person in line has at least one present to be wrapped by one of the six clerks at the counter.

2)If each person in line had one more present to be wrapped ,nine clerks would be required to guarantee that every present would be wrapped in one hour.

OA : C but i got E please explain.

here is a nice solution.

https://www.beatthegmat.com/inequality-w ... 14674.html