CMOS stands for Complementary Metal-Oxide-Semiconductor, and it refers to a type of technology used in the design and fabrication of integrated circuits (ICs). CMOS is widely used in many electronic devices due to its low power consumption, high noise immunity, and compatibility with both analog and digital signals.

CMOS devices are constructed using two types of transistors - n-type metal-oxide-semiconductor (NMOS) and p-type metal-oxide-semiconductor (PMOS). These transistors work together in a complementary manner to achieve efficient operation.

Now, let's discuss the given options and determine the correct answer:

a) Unidirectional: In CMOS technology, the flow of current can be bidirectional, meaning it can flow in both directions. This option is incorrect.

b) Bidirectional: As mentioned above, CMOS devices allow current to flow in both directions, making this option incorrect as well.

c) Directional: This option is not specific enough to provide a clear answer. CMOS devices have specific directions for current flow, depending on the circuit configuration and the specific transistor being used. Therefore, this option is also incorrect.

d) None of the mentioned: This option is the correct answer. CMOS devices are not strictly unidirectional or bidirectional, as the direction of current flow depends on the specific circuit configuration and the type of transistor being used.

In conclusion, CMOS technology allows for bidirectional current flow, making option (a) unidirectional incorrect. Option (d) None of the mentioned is the correct answer, as it accurately reflects the behavior of CMOS devices.

Unidirectional