Answer:
ZX
Explanation:
A diameter is a chord of a circle that passes through the center of the circle.
A chord of a circle is a segment inside the circle whose endpoints are on the circle.
Chords of the circle:
ZY, ZX, YW, UV
Of all those chords, only two pass through the center of the circle:
ZX, YW
Of the two diameters, only one is a choice:
ZX
Answer: B. ZX