To solve this problem, we can use trigonometry and the concept of similar triangles. Let's break it down step by step:

1. Identify the given information:
- The height of the tower is 25m.
- The distance between the observer and the tower is 23.5m.
- The height of the observer is 1.5m.

2. Define the problem:
We need to find the angle of elevation of the top of the tower from the eye of the observer.

3. Set up a diagram:
Draw a triangle representing the situation. The vertical side represents the height of the tower (25m), the horizontal side represents the distance between the observer and the tower (23.5m), and the vertical side represents the height of the observer (1.5m). Label the angle of elevation as θ.

4. Use trigonometry:
The tangent function relates the opposite side to the adjacent side of a right triangle. In this case, the tangent of the angle of elevation is the ratio of the height of the tower (opposite side) to the distance between the observer and the tower (adjacent side).
tan(θ) = opposite/adjacent
tan(θ) = 25/23.5

5. Solve for θ:
Using a calculator, we find that θ ≈ 45.19°.

6. Determine the correct answer:
The options given are A) 45°, B) 60°, C) 30°, and D) 90°. Since θ ≈ 45.19°, the closest option is A) 45°.

Therefore, the angle of elevation of the top of the tower from the eye of the observer is approximately 45°.