which is the correct definition of the term ratio

a. an amount of one thing in relation to another
b. a special mathematical number
c. a set length of time
d. a special mathematical tool

a. an amount of one thing in relation to another is the correct definition of the term ratio in the context of art. In art, a ratio is used to describe the relationship between the size or proportion of one element in relation to another element within an artwork. Ratios can be used to create a sense of balance or tension within a composition. The other options (b, c, and d) are not relevant to the art context.