What is the bond angle (in degrees) in the structure of a benzene molecule? A. 120° B. 90° C. 150° D. 60°

The correct answer is $\boxed{\text{A}}$.

The bond angle in the structure of a benzene molecule is 120°. This is because the carbon atoms in benzene are arranged in a regular hexagon, with each carbon atom bonded to two other carbon atoms and one hydrogen atom. The angle between any two adjacent carbon-carbon bonds is 120°, which is the angle formed by three equilateral triangles.

Option B is incorrect because the bond angle in a tetrahedral molecule is 109.5°. Option C is incorrect because the bond angle in a trigonal planar molecule is 120°. Option D is incorrect because the bond angle in a linear molecule is 180°.