A large company that owns a chain of gyms wanted to see if they could increase the membership in their locations by hiring full time personal trainers to work in the gyms (they do not currently employ any personal trainers). To test this, they randomly chose half of their 120 locations and hired personal trainers to work there, while the other half received no personal trainers. Which of these answers represents an element of replication in this study? a. they randomly chose half
b. 60 locations
c. while the other half received no personal trainers
d. their 120 locations