Major parts of communications systems are:

Options

A. transmitter and receiver
B. receiver and communication channel
C. transmitter and communication channel
D. transmitter, receiver and communication channel

Answer

To solve the question regarding the major parts of communication systems, we will break down the components involved in a communication system step by step.

### Step-by-Step Solution:

1. **Identify the Components of a Communication System**:
- A communication system generally consists of three main components: the transmitter, the channel, and the receiver.

2. **Transmitter**:
- The first part of the communication system is the **transmitter**. The transmitter's role is to take the original message (information) and convert it into a signal that can be transmitted over a communication channel. This involves modulation, where the message signal is altered to fit the transmission medium.

3. **Channel**:
- The second part is the **channel**. The channel is the medium through which the signal travels from the transmitter to the receiver. This can be air (for radio waves), optical fibers (for light signals), or copper wires (for electrical signals). The channel is crucial as it affects the quality and integrity of the transmitted signal.

4. **Receiver**:
- The third part is the **receiver**. The receiver's job is to capture the transmitted signal from the channel and convert it back into a form that can be understood by the user. This process often involves demodulation, where the received signal is processed to retrieve the original message.

5. **Conclusion**:
- Therefore, the major parts of a communication system are the transmitter, channel, and receiver. Based on this understanding, if we look at the options provided in the question, the correct answer would be the option that includes all three components.

6. **Final Answer**:
- The correct option is **D: Transmitter, Receiver, and Communication Channel**.