Answer:
The scientist was Ivan Pavlov
Explanation:
He was a Russian scientist, who performed multiple research on dogs. He is best know for his experiments in classical conditioning.
The best test would be a BMI. Hydrostatic weighing would just find their weight and wouldn't tell the doctor anything about the specific amount of fat on the body. There is no such thing as an MRK, and the Caliper test is a personality test. I hope this helps!
