The types of modulation which are possible are-

Options

A. one only
B. two only
C. three only
D. none of these

Answer

To solve the question regarding the types of modulation that are possible, we can follow these steps:

### Step 1: Understand the concept of modulation
Modulation is the process of varying one or more properties of a periodic waveform (the carrier signal) with respect to a modulating signal that contains information.

### Step 2: Identify the types of modulation
There are three primary types of modulation:
1. **Amplitude Modulation (AM)**: In this type, the amplitude of the carrier wave is varied in proportion to the message signal.
2. **Frequency Modulation (FM)**: Here, the frequency of the carrier wave is varied according to the message signal.
3. **Phase Modulation (PM)**: In this case, the phase of the carrier wave is varied in accordance with the message signal.

### Step 3: Summarize the types of modulation
Based on the definitions, we can summarize that the three types of modulation possible are:
- Amplitude Modulation (AM)
- Frequency Modulation (FM)
- Phase Modulation (PM)

### Step 4: Choose the correct option
From the options provided in the question, we can conclude that the correct answer is the option that lists these three types of modulation.

### Final Answer:
The types of modulation which are possible are:
1. Amplitude Modulation (AM)
2. Frequency Modulation (FM)
3. Phase Modulation (PM)

Thus, the correct option is **C**.

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