$\dfrac{103^2 - 97^2}{200}$ is equal to

1. 3

2. 4

3. 5

4. 6

By a² - b² = (a - b)(a + b) formula,

$\dfrac{103^2 - 97^2}{200} = \dfrac{(103 - 97)(103 + 97)}{200} \\[1em] = \dfrac{6 \times 200}{200} \\[1em] = 6.$

Hence, Option 4 is the correct option.