Introduction:
In CISC (Complex Instruction Set Computer) architecture, the processor is designed to execute a wide range of complex instructions. These instructions are stored in various components of the system. Among these components, the complex instructions are primarily stored in transistors.

Explanation:
In CISC architecture, the focus is on providing a rich set of instructions that can perform complex operations. These instructions are designed to be executed directly by the processor. To store these complex instructions, transistors are used.

Transistors:
Transistors are semiconductor devices that can amplify or switch electronic signals and electrical power. They are the fundamental building blocks of modern electronic devices and integrated circuits (ICs). In CISC architecture, transistors are used to store complex instructions in the form of logic gates. These logic gates are combined to form the desired instruction set.

CMOS:
CMOS (Complementary Metal-Oxide-Semiconductor) is a technology used to implement transistors. It is a type of semiconductor technology that uses both p-type and n-type MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) to create logic gates and memory cells. While CMOS technology is used in the implementation of transistors, it is not directly responsible for storing complex instructions in CISC architecture.

Register:
Registers are high-speed storage locations within the processor that are used to hold data and instructions temporarily. They are used to store intermediate results during the execution of instructions. While registers play a crucial role in the execution of complex instructions, they are not the primary storage location for these instructions in CISC architecture.

Diodes:
Diodes are electronic components that allow current to flow in only one direction. They are used in various applications such as rectification, signal modulation, and switching. However, in CISC architecture, diodes are not primarily used to store complex instructions.

Conclusion:
In CISC architecture, the complex instructions are primarily stored in transistors. Transistors, implemented using CMOS technology, form the logic gates that store and execute these instructions. While registers play a crucial role in the execution of these instructions, they are not the primary storage location. Diodes, on the other hand, are not directly involved in the storage of complex instructions in CISC architecture.