For Joan's Doctoral Dissertation Experiment,15 Wheelchair Users Were Randomly Assigned

For Joan's doctoral dissertation experiment,15 wheelchair users were randomly assigned to three groups with 5 in each group.These participants navigated in virtual-reality settings.Group 1 participants were in the virtual-reality setting (a building) as wheelchair users.Group 2 participants were in the virtual-reality setting in a wheelchair pushed by a walking person.Group 3 participants walked without aid in the virtual-reality setting.Joan measured the time each participant needed to complete the navigation of the virtual-reality setting.What are the dependent and independent variables?

A) Independent = wheelchair use;dependent = virtual-reality condition
B) Independent = wheelchair use;dependent = time needed
C) Independent = time needed;dependent = virtual-reality condition
D) Independent = virtual-reality condition;dependent = time needed