Which of the following is NOT a kind of ‘sign’ as suggested by Charles sanders pierce?

The correct option is Visual.

Charles Sanders Peirce, a pioneering philosopher and logician, developed a foundational triadic model of semiotics (the study of signs). In his framework, he classified signs into three fundamental categories based on how the sign relates to its object:
1. Icon: A sign that represents its object through direct resemblance or likeness (such as a portrait, a photograph, or a map).
2. Index: A sign that is physically or causally connected to its object (such as smoke indicating fire, a footprint indicating a passerby, or a medical symptom indicating a disease).
3. Symbol: A sign that relates to its object purely through social convention, rule, or habit, with no physical connection or resemblance (such as spoken or written words, numbers, or national flags).

In this classification system, Visual describes a sensory channel or medium through which a sign is perceived (by sight), rather than a semiotic relationship between a sign and its referent. Thus, "Visual" is not a type of sign in Peirce's triadic model.