Study the given pattern carefully and select the number that can replace the question mark (?) in it.

Correct option is B

Concept: addition the square of bottom number then divides by 2.
:
$$Solution:\frac{(3)^2 + (3)^2}{2} = 9 \\\frac{(3)^2 + (9)^2}{2} = 45 \\\frac{(4)^2 + (6)^2}{2} = 26 \\\frac{(2)^2 + (2)^2}{2} = 4$$​

Final answer (b) 4.