Answer:
The correct answer option is C. 12/13.
Explanation:
We are given a right angled triangle with two known sides and we are to find the measure of the angle O.
For finding the measure of O, we will use sine for which we need to find the value of the value of the hypotenuse (MO).

Now that we know the length of the hypotenuse, we can find sin (O).

Therefore, the correct answer option is C. 12/13.