Toby is afraid of frogs. Which of the following most likely would allow Toby to be desensitized to the frogs and remove his fear?

Place a real bullfrog on his desk in a cage for him to be near.

Force Toby to sit on a frog when he gets to the desk.

Dump a bag of baby frogs into the room and allow Toby to leap with them.

Place ceramic frogs around the room so that he would encounter the frogs in a nonthreatening way.