What is the musical function of the term "m.s."?

The term "m.s." stands for "manu sinistra," which is a Latin term meaning "left hand" in musical notation. This designation is particularly important in the context of piano music, where it specifies that a passage should be played with the left hand. Utilizing “m.s.” helps performers understand which hand is required for specific sections of a piece, allowing for more accurate interpretation and execution of the music.

The other options may refer to other common musical terms, such as dynamics for loudness and softness, or playing techniques applicable to different instruments, but they do not address the specific meaning of "m.s." The focus on the left hand in this case is what makes this term particularly relevant for pianists and musicians performing music that requires clear hand separation for clarity and expression.