Indicate which one of the following system is digital

Options

A. pulse position modulation
B. pulse code modulation
C. pulse width modulation
D. pulse amplitude modulation

Answer

To determine which of the following systems is digital, we need to analyze the options given. In this case, the correct answer is "Pulse Code Modulation (PCM)."

### Step-by-Step Solution:

1. **Understanding Digital Systems**:
- Digital systems process data in discrete values (0s and 1s), as opposed to analog systems which process continuous signals.

2. **Identifying the Options**:
- We need to look at the options provided (though they are not listed here, we will focus on PCM as a known digital system).

3. **Defining Pulse Code Modulation (PCM)**:
- PCM is a method used to digitally represent sampled analog signals. It involves sampling an analog signal at regular intervals and converting these samples into a digital format.

4. **Applications of PCM**:
- PCM is widely used in various applications such as:
- Digital audio (e.g., CDs)
- Digital telephony
- Other forms of digital communication.

5. **Conclusion**:
- Since PCM is a method that converts analog signals into a digital format, it qualifies as a digital system. Therefore, the correct answer to the question is Pulse Code Modulation.