The question refers to a circuit and waveform options, but the essential diagram/images are missing:

• the circuit is not shown,
• the input waveform is not shown,
• options A, B, C, D are blank.

So the waveform across $R$ cannot be determined uniquely from the text alone.

What is needed

To solve this, I need:

1. the circuit diagram,
2. the polarity/orientation of the ideal diode,
3. the applied input waveform,
4. the actual waveform options A–D.

Why it cannot be solved uniquely

For an ideal diode circuit, the output across a resistor depends critically on:

• whether the diode is in series or shunt,
• the direction of the diode,
• whether the source is AC / square / triangular / sinusoidal,
• where exactly the resistor is placed.

Different diode orientations can give completely different outputs such as:

• positive half-wave only,
• negative half-wave only,
• clipped waveform,
• full input waveform,
• zero output during some intervals.

Hence, without the diagram, any choice among A–D would be a guess.

Comparison with stored answer

The stored correct answer is D, but since the required figures are absent, I cannot verify that rigorously.