Explanation:

- The amount after 2 years with compound interest is Rs.7436.

- The interest rate given is 4% per annum.

- To find the original sum (principal), use the compound interest formula:

$$A=P{(1+\frac{r}{100})}^n$$

where $A=7436$, $r=4$, $n=2$.

- Rearrange formula and solve for P:

$$7436=P{(1+\frac{4}{100})}^2$$

$$7436=P\times (1.04{)}^2$$

$$7436=P\times 1.0816$$

$$P=\frac{7436}{1.0816}\approx 6875$$

- Calculation shows the original sum was Rs.6,875.

- Correct Answer: Option 4: Rs.6,875