DrYagushi Is Researching the Effects of Daily Exercise on Neurogenesis

Multiple Choice

Dr.Yagushi is researching the effects of daily exercise on neurogenesis.To do this,she uses three groups of rats that vary in the amount of daily exercise: one group gets no access to a running wheel,another group gets 2 hours of access to the running wheel,and a final group gets 12 hours of access to the wheel.After 2 months on their respective exercise schedules,the rats are sacrificed,and Dr.Yagushi counts the number of neurons in a given region of the brain.Most importantly,when Dr.Yagushi is doing her neuron count on each brain slice,she doesn't know which brain received each exercise level.What potential influence on the results is Dr.Yagushi mindful of in collecting her data this way?

A) sampling bias
B) demand characteristics
C) researcher bias
D) participant bias