Identify the kind of noun in bold. 

Patrick was sad because he failed his class. 

Option C is the correct option. "Sad is an abstract noun. The name of the qualities of persons, animals, or things is known as an abstract noun. A noun is the name of a person, place, animal or thing. An abstract noun denotes the name of ideas, feelings, quality or state rather than a concrete object. It names intangible items rather than tangible items. Example of abstract nouns includes kindness, strength, affection, hurt, anger, etc.