The Experiment Is Run Once for Each Combination of Brand

Multiple Choice

The experiment is run once for each combination of brand of AAA batteries and device (TV remote, hand-held game, flashlight and digital camera) .The twelve runs are ordered
Randomly.The time (in minutes) that each battery lasts under continuous usage is recorded.
Which of the following statements is true about this design?

A) The devices serve as blocks to account for the variability between the lengths of time batteries last in different devices.
B) This is a completely randomized design in one factor.
C) The interaction effect between brand of battery and type of device is significant.
D) This is an observational study.
E) This is a retrospective study.