Concept:The electromagnetic spectrum includes all types of electromagnetic radiation, such as radio waves, X-rays, gamma rays, and visible light.
Explanation:Electromagnetic waves do not require a material medium to travel.
Examples of such waves are X-rays and gamma rays.
Sound waves and water waves are mechanical waves, not electromagnetic waves.
So, from the listed options, the correct pair must consist of two electromagnetic waves.
Both X-rays and gamma rays belong to the electromagnetic spectrum.
Answer:The correct pair is II and IV — option D.