Answer :

To solve the subtraction

$$10 - 0.43,$$

follow these steps:

1. Rewrite $10$ as $10.00$ so that both numbers have the same number of decimal places:

$$10.00 - 0.43.$$

2. Subtract column by column starting from the rightmost digit. In the hundredths place: subtract $3$ from $0$. Since $0$ is less than $3$, borrow $1$ (which is $10$ hundredths) from the tenths place.

3. After borrowing, the hundredths column becomes $10 - 3 = 7$, and the tenths column decreases by $1$.

4. In the tenths place, you now have to subtract $4$ from the reduced digit. With proper borrowing and subtraction, the final result becomes:

$$10.00 - 0.43 = 9.57.$$

Therefore, the final answer is $\boxed{9.57}$, which corresponds to option B.