The question refers to "the circuit shown here" and asks which graph/representation of $V_{AB}$ is correct. However, the actual circuit diagram and the missing option figures for A, B, and D are not provided in the prompt.

So, a complete derivation is not possible from the given text alone. In such diode-circuit questions, the exact answer depends critically on:

1. How the diode(s) are connected
2. Whether the source is AC/DC and its waveform
3. The positions of points $A$ and $B$
4. What the graphical options A, B, D actually show

Without these, we cannot independently reconstruct $V_{AB}$.

What can still be concluded

The only explicit option visible is:

• C: $V_{AB}$ would be zero at all times.

Since the stored correct answer is B, that means option C is not correct.

But because the circuit and option figures are missing, I cannot rigorously verify whether B is truly correct from first principles.

Comparison with stored answer

Because the essential diagram is absent, I cannot derive the answer independently with certainty. Therefore I cannot honestly confirm agreement based on physics analysis alone.

If you provide the circuit image and all option graphs, I can solve it fully step-by-step and verify option B properly.