Julie is tired of picking up her five-year-old son's toys every day. She has decided to use operant conditioning to train him to pick up his own toys. Her friend recommends the use of primary positive reinforcement.
Which of the following BEST describes a way Julie could use primary positive reinforcement to encourage her son to
pick up his toys?

Which statement best describes lymph? a. a clear fluid that carries proteins, water, white blood cells, fat, dead cells, and toxins that drain from the fluid between the cells of the body b. a clear fluid in the cells that to secrete and transport hormones from one region of the body to another c. a thick, opaque, and yellowish fluid that is present when there is an infection in the body d. a clear, liquid component of blood that contains red blood cells, white blood cells, platelets, and iron