Question

how can we control for the possible effects of the stress of oral injection and the injected oil when evaluating the effects of treatments 1 and 2?
a) compare treatment 1 and 2 rabbits to rabbits receiving no injection
b) compare treatment 1 and 2 rabbits to rabbits injected orally with oil mixed with banana
c) compare treatment 1 and 2 rabbits to rabbits in treatment 3
d) compare treatment 1 and 2 rabbits to rabbits injected with estrogen mixed with banana

Explanation:

Answer:

B. Compare treatment 1 and 2 rabbits to rabbits injected orally with oil mixed with banana