An assembly line with 30 activities is to be balanced. The total amount of time required for all 30 activities is 45 minutes. The line will operate for 420 minutes per day. Which of the following must be the cycle time to achieve an output rate of 300 units/day?
a. 0.80 minutes
b. 1.4 minutes
c. 2.4 minutes
d. 3.0 minutes