Which of the following best describes the term 'macule'?

The term 'macule' refers specifically to a flat, discolored area on the skin that is typically less than 1 centimeter in diameter. It is important to note that macules are not raised or elevated; they are level with the surrounding skin but differentiated by their color, which can be due to various factors such as pigmentation changes or vascular lesions.

The choice describing an elevated area of skin refers instead to a papule or nodule, while thickening of the skin is more indicative of hyperkeratosis or a plaque. The mention of a small visible blood vessel describes a telangiectasia or spider vein, which does not fit the definition of a macule. Therefore, the description of a flat, discolored spot accurately captures the characteristics of a macule, distinguishing it from other skin lesions.