A Succession Of Pitches Perceived As A Unity Is Called

A succession of pitches perceived as a unity is called:?

c. A melody.

Note that is says a "succession." That implies one note after another in a series.

Also, see the dictionary definitions below. For example, one of the definitions is, "a succession of notes forming a distinctive sequence; tune." Another is, "a rhythmic succession of single tones organized as an aesthetic whole"