Centurion Processing Finishes the First Unit in 100 Hours and Learns

Multiple Choice

Centurion Processing finishes the first unit in 100 hours and learns at a 75% rate.Their competitor,Ochenta Incorporated,completes their fist unit in 80 hours but learns at an 80% rate.If they match total output with each other how many more units must each fierce rival make before Centurion is faster than Ochenta?

A) four more
B) six more
C) eight more
D) ten more