The median of first 8 prime numbers is:

1. 7

2. 9

3. 11

4. 13

Prime numbers : 2, 3, 5, 7, 11, 13, 17, 19

No. of terms (n) = 8, which is even.

By formula,

Median = $\dfrac{\dfrac{\text{n}}{2} \text{ th observation} + \Big(\dfrac{\text{n}}{2} + 1\Big) \text{ th observation}}{2}$

Substituting values we get:

$= \dfrac{\dfrac{8}{2} \text{ th observation} + \Big(\dfrac{8}{2} + 1\Big) \text{ th observation}}{2} \\[1em] = \dfrac{4 \text{ th observation} + \Big(4 + 1\Big) \text{ rth observation}}{2} \\[1em] = \dfrac{4 \text{ th observation} + 5 \text{ th observation}}{2} \\[1em] = \dfrac{7 + 11}{2} \\[1em] = \dfrac{18}{2} \\[1em] = 9.$

Hence, Option 2 is the correct option.