To understand why the primary storage is considered "Faster and more expensive" than secondary storage, let's delve into the basic concepts of computer storage hierarchy.

Primary Storage: Also known as main memory or RAM (Random Access Memory), it is the memory that a computer can access directly and immediately. This type of memory is volatile, meaning it requires power to maintain the stored information. When the computer is turned off, the data in primary storage is lost. Primary storage is used to store data and instructions that are actively being used by the CPU.

• Speed: Primary storage is much faster in terms of data access speed compared to secondary storage. This speed is crucial for the performance of computing tasks as it allows quick loading and execution of applications and processes.
• Cost: Due to the high-speed operation, primary storage is also more expensive per unit of storage capacity compared to secondary storage options.

Secondary Storage: This refers to storage devices that provide non-volatile memory for storing persistent data. Common examples include hard drives, solid-state drives, and flash drives. Secondary storage retains data even when the computer is powered off.

• Speed: Secondary storage devices are generally slower as they involve mechanical parts (in the case of HDDs) or different technology that doesn't match RAM speeds. They are designed for long-term storage rather than quick access.
• Cost: These are cheaper compared to primary storage, making them suitable for storing larger amounts of data economically.

With this understanding, let's evaluate the options:

1. Slower and lesser expensive: Incorrect. Primary storage is not slower, although it is lesser in quantity due to cost.
2. Faster and lesser expensive: Incorrect. While it's true that primary storage is faster, it is not less expensive.
3. Slower and more expensive: Incorrect. Primary storage is faster, not slower.
4. Faster and more expensive: Correct. This correctly describes primary storage which is indeed faster in speed but more expensive than secondary storage.

Conclusion: Thus, based on the above analysis, the correct answer is that primary storage is faster and more expensive than secondary storage.