In this question it has been clearly indicated that AZB is to be taken as an arc. This is because there is the arc symbol on top of AZB. Thus, we have
and we need to answer what does the arc
represent.
As we can see from the diagram, by visual inspection, that AZ is the chord which is lesser than the diameter and AZB is the segment on that lesser side of the circle. Therefore, the arc
must be the minor arc.
Therefore, Option A, minor arc is the correct answer.