1. **Problem:** In a right triangle, the opposite side to angle $\theta$ is 7 and the hypotenuse is 25. Find $\sin \theta$. 2. **Formula:** $\sin \theta = \frac{\text{opposite}}{\text{hypotenuse}}$ 3. **Calculation:** Substitute the given values: $$\sin \theta = \frac{7}{25}$$ 4. **Explanation:** The sine of an angle in a right triangle is the ratio of the length of the side opposite the angle to the length of the hypotenuse. 5. **Answer:** $\sin \theta = \frac{7}{25}$, which corresponds to option (A).