Which term is the name for the lowest note in a triad?

A. root
B. third
C. fifth
D. seventh

A. root

The term for the lowest note in a triad is the "root." So, the correct option is A. root.

The lowest note in a triad is called the root.

To find the answer, it is helpful to understand what a triad is. A triad is a chord consisting of three notes - a root, a third, and a fifth. The root is the starting pitch or the foundation of the chord. In a triad, the root is always the lowest note.

So, option A, "root," is the correct answer.