Answer:
C.
![54^o](https://img.qammunity.org/2019/formulas/mathematics/college/5nuxxrneza7qrr2rs1n9d4aaoqdp10wtzr.png)
Explanation:
We have been given a circle O. AB and AC are tangent of our given circle.
Since angle B is formed by tangents outside our given circle, so we will use tangent-tangent theorem.
Tangent-Tangent theorem states that when an angle is formed outside the circle by two tangents, then the measure of angle equals half the difference of its corresponding arcs.
![m\angle B=\frac{\text{Major arc - Minor arc}}{2}](https://img.qammunity.org/2019/formulas/mathematics/college/tyf9pbtgo07y7avoaokyw7omb9nxkv38u4.png)
![m\angle B=(234^o-126^o)/(2)](https://img.qammunity.org/2019/formulas/mathematics/college/lmvax8l3hgbxfrmvampmbi7o6nfaqa3l6t.png)
Therefore, the measure of angle B is 54 degrees and option C is the correct choice.