An instruction cycle consists of fetching, decoding, executing, and storing. Let's understand each step in detail:

1. Fetching:
- During the fetching phase, the CPU (Central Processing Unit) fetches the instruction from the memory.
- The program counter (PC) contains the address of the instruction to be fetched.
- The CPU sends a request to the memory to retrieve the instruction at that address.
- The instruction is loaded into the instruction register (IR) within the CPU.

2. Decoding:
- In the decoding phase, the CPU interprets the fetched instruction.
- The instruction in the IR is decoded to determine the operation to be performed.
- The CPU identifies the opcode (operation code) and any associated operands or addressing modes.

3. Executing:
- Once the instruction is decoded, the CPU carries out the necessary operations specified by the instruction.
- This phase involves performing arithmetic or logical operations, data manipulation, or control flow changes.
- The ALU (Arithmetic Logic Unit) within the CPU is responsible for executing the instruction.

4. Storing:
- During the storing phase, the CPU may update the memory or register values based on the results of the executed instruction.
- If the instruction involves storing data in memory, the CPU writes the result back to the memory.
- If the instruction involves storing data in a register, the CPU updates the register with the result.

5. Conclusion:
- The instruction cycle consists of all these steps, which are performed sequentially for each instruction.
- After the storing phase, the program counter is updated to point to the next instruction in memory.
- The CPU then repeats the cycle, fetching the next instruction and continuing the process.

Therefore, option 'C' (fetching, decoding, executing, and storing) is the correct answer as it includes all the necessary steps involved in an instruction cycle.