A dog trainer gives a dog a treat every third time the dog sits after the trainer says "sit." What BEST describes the schedule of reinforcement under which the trainer is controlling the dog's behavior? a. Fixed ratio b. Variable interval c. Variable ratio d. Fixed interval

C

Explanation:

answer; /// i believe that the correct answer is; ///a combination of the birth and death

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."