Which term best describes a major arc of a circle that has the same starting and ending pointa. circumfrenceb. diameterc. radiusd. chord?

An arc is defined as the portion of the circle defined by two distinct points on the circle. Think of a plate and if you pick two points on the outer edge and connect them via the edge, you will get a curve which is an arc. If you pick two points opposite of each other you will get an arc of pi. If you pick a point that is both the start and the ending point, then you will just trace the entire cricle and this is simply equivalent to the circumference.