Researchers at a veterinary hospital wish to test a new drug developed for treating degenerative joint disease (DJD) in dogs. A group of 30 Great Danes, 50 Labradors, and 40 Mastiffs is to be used. The researchers randomly assign 15 of the Great Danes, 25 of the Labradors, and 20 of the Mastiffs to the traditional drug for treatment. The remaining dogs are assigned to the new drug. The major reason for separate assignment for each breed of dog is that A) This is a large study with 120 dogs.
B) This design uses matched pairs to detect the new-drug effect.
C) The new drug may affect Great Danes, Labradors, and Mastiffs differently.
D) The new drug may affect dogs with DJD differently than dogs without DJD.
E) There must be an equal number of dogs in each of the two treatment groups.

Testing a new drug developed for treating degenerative joint disease (DJD) in dogs

The major reason for separate assignment for each breed of dog is that:

E) There must be an equal number of dogs in each of the two treatment groups.

Step-by-step explanation:

One of the two groups is the experimental group (treatment group).  It receives the new treatment whose effect the researchers are interested in finding out.  The other half (group) is called the control group.  It receives the traditional drug.  This control group (also called the comparison group) ensures that the treatment the researchers are giving to the dogs causes the expected experimental results.  This means that the results of the two groups are compared to determine the different effects.

22 and 22

step-by-step explanation:

10 plus 12 equals 22.

12 plus 10 also equals 22 because regardless of what order they're in, they're gonna equal the same thing.