Final answer:
Computer code is the sole option not considered a tangible medium of original expression, as it is intangible, contrasting with physical mediums like paper, canvas, and sculpture.
Step-by-step explanation:
The question "Which of the following is not considered a tangible medium of original expression?" asks us to identify from the given options which one is not a physical medium used to express creativity or original thoughts. Of the options provided - canvas, paper, computer code, and sculpture - the one that is not considered a tangible (physical) medium is computer code. While canvas, paper, and sculpture are traditional arts media, known for their physical existence, computer code is intangible and represents digital instructions or information rather than physical artwork. This does not diminish its value as a medium for expression, especially in digital art forms, but it does differentiate it from physical mediums such as paper sculpture or paintings on canvas, which rely on physical materials such as oil and pigments. The tactile nature of materials like paper or marble is a fundamental determinant of the aesthetic and sensory qualities of traditional art pieces.