Introduction:
The comparison is being made between a p-n junction diode and a Schottky diode, both of the same rating. The question asks to identify the characteristic that is higher in the Schottky diode compared to the p-n junction diode.

Explanation:
To understand the comparison, let's discuss each option one by one.

1. Higher cut-in voltage:
The cut-in voltage is the voltage at which a diode starts conducting current. In the case of a p-n junction diode, the cut-in voltage is typically around 0.6-0.7 volts for silicon diodes. On the other hand, a Schottky diode has a lower cut-in voltage, typically around 0.2-0.3 volts. Therefore, option 'a' is incorrect.

2. Lower reverse leakage current:
Reverse leakage current is the small current that flows in the reverse direction when a voltage is applied in the opposite polarity. Schottky diodes have a lower reverse leakage current compared to p-n junction diodes. This is because Schottky diodes have a majority carrier mechanism for conduction, resulting in less leakage current. Therefore, option 'b' is incorrect.

3. Higher operating frequency:
The operating frequency of a diode depends on its switching speed. Schottky diodes have a faster switching speed compared to p-n junction diodes. This is due to the absence of a depletion region in Schottky diodes, which reduces the capacitance and allows for faster switching. As a result, Schottky diodes can operate at higher frequencies. Therefore, option 'c' is correct.

4. Higher switching time:
Switching time refers to the time taken for a diode to transition between the forward and reverse bias states. Schottky diodes have a lower switching time compared to p-n junction diodes. This is because Schottky diodes have a majority carrier mechanism, which allows for faster switching. Therefore, option 'd' is incorrect.

Conclusion:
Among the given options, the correct answer is option 'c' - a Schottky diode has a higher operating frequency compared to a p-n junction diode of the same rating. This is due to the faster switching speed of Schottky diodes, which is a result of their majority carrier mechanism and absence of a depletion region.