I believe it is A? I've never done this before so...
Articulation in music is centered around the flow or continuity of groups of notes; they can be smoothly linked together or played separately with small pausing between each note, for example. A variety of terms exist to convey articulation, such as staccato.
So in this question, the response that relates most to articulation is answer C, how smoothly or detached a musical line is played.
