Answer:
Option 4
Explanation:
"Angle formed between a secant and a tangent at a point outside a circle is equal to half of the difference of the measure of the intercepted arcs"
By applying this theorem in the figure given in the picture,
m∠RST =
![(1)/(2)[\text{m(arc TU - m(arc RT))}]](https://img.qammunity.org/2022/formulas/mathematics/high-school/f6y5ocdfbvl0oxlb411v98jnfkhy11hb3t.png)



Therefore, Option 4 is the correct option.