These signals are represented by a continuous waveform:

The correct choice is based on the definition of signal types in the context of waveform representation. Analog signals are characterized by a continuous waveform, meaning they can take on an infinite number of values within a given range. This continuous nature allows for smooth transitions between values, making analog signals ideal for representing real-world phenomena, such as sound and light, which vary smoothly over time.

In contrast, digital signals are represented by discrete values, typically in binary form, which results in non-continuous waveforms that oscillate between two states (usually represented as 0s and 1s). Options like laser and optical do not specifically refer to the waveform representation but rather to methods of signal transmission or types of signals that can include analog or digital formats.

Understanding that analog signals are inherently continuous is key to grasping why this choice is appropriate in the context of waveform representation.