If $$\cos\left(A - B\right) = \frac{\sqrt{3}}{2}$$ and $$\sec A, 0^{\circ} \leq A \leq 90^{\circ}, 0^{\circ} \leq B \leq 90^{\circ}$$ then what is the measure of B?

A

$$60^{\circ}$$

B

$$0^{\circ}$$

C

$$30^{\circ}$$

D

$$90^{\circ}$$