The index number of the base year is :

The correct answer is Option (2) → 100

An index number compares a value with its value in the base year:

    \( \displaystyle \text{Index} = \frac{\text{value in the current year}}{\text{value in the base year}} \times 100 \)

For the base year itself the two values are the same, so

    \( \displaystyle \text{Index} = \frac{p_0}{p_0} \times 100 = 100 \)

Note: This topic was not in the CUET 2026 syllabus.