Which word does not belong to the other three?

Pratyaksha: 

• In Indian logic, it is a type of pramana
• Pramana means the way to get accurate and true knowledge
• It can get through a direct way or anubhava or sense and an indirect way or smriti, based on previous knowledge or experience.

Senses:

• The sensory system helps us to perceive the world.
• It is a compound effect of sensory receptors
• Perception is made possible by the sensory system
• Sensory receptors detect sensory stimuli and convert them into electrical signals that can be interpreted by the brain
• There are five sensory receptors, eye, ear, nose, tongue, and skin.
• The capacity to think is considered as the sixth sense

Functions of sensory organs:

Thinking is not a direct way to get knowledge. It is not considered as a function of five sensory organs.