Of the following circuits, the one which involves storage is

Answer: Option A

In the given options, the circuit that involves storage is the RS Latch (Reset-Set Latch). An RS Latch is a basic bistable digital circuit with two stable states that can store a single bit of data. It is commonly used in digital electronics for memory and storage applications.

Here's a brief explanation of the options:

RS Latch (Option A): As mentioned earlier, it is a fundamental storage element. It has two inputs: the Set (S) input and the Reset (R) input, and two outputs: Q and Q' (complement of Q). It can hold one bit of information.

Mux (Option B - Multiplexer): A multiplexer is used to select one of many inputs and route it to a single output. While it can be used to transfer data, it is not primarily designed for storage.

Nand (Option C - NAND gate): A NAND gate is a basic logic gate that performs logical conjunction (AND) followed by logical negation (NOT). It is used for various logic operations but is not a storage device.

Decoder (Option D): A decoder is used to convert a binary code into a set of output lines. It doesn't store data but is used for addressing and control purposes.

So, the correct answer is Option A: RS Latch, which is a circuit involving storage of a single bit of data.