Final answer:
A character piece is a rather short piano work, often in free form that conveys a particular mood or character. These pieces are expressive and may be inspired by various nonmusical ideas.
Step-by-step explanation:
A character piece is a type of work in the music genre. Specifically, it refers to c. rather short piano work, often in free form. Character pieces are usually solo piano compositions that convey a particular mood or character, much like a musical portrait. They do not adhere to strict formal structures but are expressive and often improvisational in nature. These pieces can also be inspired by nonmusical ideas such as literature, art, or personal experiences, hence sometimes they align with option d. Examples of character pieces include Frédéric Chopin's Préludes or Robert Schumann's Kinderszenen (Scenes from Childhood). While they can sometimes reflect the character of an eccentric composer, option a, that's not a defining characteristic of the form, and they are not necessarily a type of chamber music work, aria, or have to be inspired by a nonmusical idea, which rules out options b, e, and partially d.