In my day (my next door neighbor was a brontosaurus rex), there was a wheel on the front panel.
You shorted the input leads when the master switch was turned to ohms. Then you adjusted the wheel so that the meter read 0 on the right hand side of the scale. The zero is clearly marked. The ohmmeter on an analog Vom reads 0 on the right. Everything else has its zero on the left.
The correct answer is C.
By shorting the test leads rotating the Ohms Adjust knob until the pointer indicates 0 Ohm
Please see attached image.
I think what you are trying to achieve is to calibrate the Ohm meters section of the analog multimeter using the zero-ohm adjuster.
A. By rotating the OHMS ADJust knob until the pointer is set over 0 volts, without shorting the test leads
This option is wrong because the zero-ohm adjuster cannot not work when the selector knob of the analog meter is set to the Voltmeter section. The test leads need to be shorted too for you to carry out the calibration procedure. Keep in mind that we are trying to measure resistance, not voltage so this option is wrong.
B. By rotating the OHMS ADJust knob until the pointer is set over 0 ohms, without shorting the test leads
This option is also wrong. Thought the selector knob is set to the Ohmmeter section of the analog meter, you cannot calibrate the Ohmmeter without shorting the test leads. Shorting the test leads shows you the current Resistance reading of the Ohmmeter as you adjust the zero Ohm adjuster.
C. By shorting the test leads and rotating the OHMS ADJust knob until the pointer indicates 0 ohms
This option will give you the correct answer. By shorting the test leads of the meter, you are able to see the current Resistance reading in Ohm as you adjust the zero adjuster knob to get the desired 0 Ohms
D. By shorting the test leads and rotating the OHMS ADJust knob until the pointer indicates 0 volts
This option is wrong. Though the test leads were shorted in this option and the zero adjust knob was rotated. The pointer is supposed to indicate 0 Ohms not 0 Volts. Keep in mind that we are trying to calibrate the meter to measure Resistance in Ohms, not Volts.