An oscilloscope is an instrument that allows us to visualize and analyze waves. It is commonly used in various scientific and engineering fields to study and measure electrical signals. A correct understanding of the options provided will help us identify the correct answer.

Option 1: Visible light is a type of electromagnetic wave that falls within the range of wavelengths our eyes can perceive. While some oscilloscopes may have the ability to measure light intensity, they primarily focus on analyzing electrical signals; therefore, option 1 is not the correct answer.

Option 2: X-rays are another type of electromagnetic wave, but they have much higher energy and shorter wavelengths than visible light. Oscilloscopes are not designed to detect X-rays, so option 2 is not the correct answer.

Option 3: Sound waves are mechanical waves that require a medium, such as air, water, or solid, for propagation. Oscilloscopes can measure and display electrical signals that correspond to sound waves, making option 3 the correct answer.

Option 4: Gamma rays are very high-energy electromagnetic waves that are typically emitted from radioactive materials or nuclear reactions. Like X-rays, gamma rays are not within the scope of measurement for oscilloscopes, so option 4 is not the correct answer.