As cats age, they can sutter a decine in cognitive functioning memory, the ability to learn awareness, sit and heang can all deteriorate. a study is to be conducted to determine which of two medicines. any credase inhibitor is more effective in promoting cognitive health and reducing the onset of feine cognitive atunction researchers will randomly select 150 cats from 10 or a monoamine will be more than 10 years old, and the owners have given consent to participate in the study changes in cognitive health will be evaluated atter six months of treatment rentage veterinary practices wound the country all the cas part a: what would be an advantage of adding a control group to the design of the study? (2 points) part 1: assuming a control group is added, explain how you would assign the 150 cats to the three treatment groups for a completely randomized design (4 points) part c: rather than using a completely randomized design one group of researchers proposes blocking on veterinary clinics whereas another group of researchers wants to block on breed of cat how would you decide which one of these two variables to use as a blocking variable? (4 points)