The base of the Decimal Number System is 10, and it consists of ten digits from 0 to 9.

Understanding the Decimal Number System
The Decimal Number System is one of the most widely used numerical systems in everyday life. Here’s a detailed explanation of why its base is 10.

What is a Base?
- The base of a number system indicates how many unique digits, including zero, are used to represent numbers.
- For example, in a base-2 (binary) system, there are 2 digits: 0 and 1. In a base-16 (hexadecimal) system, there are 16 digits: 0-9 and A-F.

Decimal System Basics
- The Decimal Number System is also known as the base-10 system.
- It employs ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.
- Each position in a decimal number represents a power of 10.

Why Base 10?
- The reason we use base-10 is largely historical and practical.
- It is believed that humans originally counted using their fingers, leading to the adoption of ten as a natural base.
- In terms of calculations, base-10 is user-friendly and intuitive for most mathematical operations.

Examples of Decimal Representation
- The number 345 in the decimal system can be broken down as:
- 3 × 10² + 4 × 10¹ + 5 × 10⁰
- This illustrates how each digit’s position corresponds to a power of 10.

Conclusion
- Therefore, the correct answer to the question is option 'C' because the Decimal Number System is fundamentally based on the number 10.
- Understanding the base allows for better comprehension of how numbers are structured and calculated in our everyday lives.