In a $$\triangle$$ XYZ. XO is the median and $$XO =\frac{1}{2}YZ$$. If $$\angle YXO = 30^{\circ}$$. then what is the value of LXYZ ?

A

$$15^{\circ}$$

B

$$90^{\circ}$$

C

$$30^{\circ}$$

D

$$60^{\circ}$$