Among the options provided, the one that can be classified as a transverse wave is:
A. X-Ray
X-rays are electromagnetic waves, which are inherently transverse waves. In transverse waves, the oscillations occur perpendicular to the direction of wave propagation.
The other options, such as sound waves and sonic booms (which are types of pressure waves) and shock waves, are classified as longitudinal waves, where the oscillations occur in the same direction as wave propagation.