Final answer:
The golden ratio is evident in both the Parthenon and the iPod, representing proportion in art and design.
Step-by-step explanation:
The answer to the question is a) Proportion.
The golden ratio is a mathematical concept that is evident in both the Parthenon and the iPod. It refers to a specific proportion, approximately 1.618, that is believed to be visually pleasing. In the Parthenon, the architects used the golden ratio to determine the height and width of the building, resulting in a balanced and aesthetically pleasing structure. Similarly, in the design of the iPod, Apple applied the golden ratio to create a harmonious and visually appealing product.