What is a plagal cadence?

• A. A cadence moving from subdominant to tonic (IV-I).
• B. A cadence from dominant to tonic (V-I).
• C. A cadence from tonic to dominant (I-V).
• D. A cadence from submediant to dominant (VI-V).

Answer: (A)

A plagal cadence is the harmony that ends a phrase by moving from the subdominant to the tonic. In Roman numerals, that’s IV going to I. This IV–I motion gives a softer, more relaxed sense of resolution compared with a stronger, more decisive finish.

That’s why this option fits best: it explicitly describes moving from the subdominant to the tonic, which is the defining characteristic of a plagal cadence. By contrast, a dominant-to-tonic move (V–I) is the authentic cadence with a stronger pull to the tonic; tonic-to-dominant (I–V) suggests a direction toward continuing rather than final closure; and a movement from submediant to dominant (VI–V) isn’t the standard cadence used to end a phrase.