Explanation:

To find the cost of levelling the triangular field, we need to calculate its area using Heron's formula and then multiply by the cost per square meter. Here’s the approach:

- Find the semi-perimeter (s):

$$

s = \frac{(96 + 110 + 146)}{2} = 176

$$

- Calculate the area (A) using Heron’s formula:

$$

A = \sqrt{s(s-96)(s-110)(s-146)}

$$

$$

A = \sqrt{176 \times 80 \times 66 \times 30} = 5280 \text{ m}^2

$$

- Calculate the cost of levelling:

$$

\text{Cost} = 5280 \times 5.60 = 29,568 \text{ Rs}

$$

- Correct option:

- Option 4: Rs29,568