It is B.
The underlined ≥ symbols a closed circle, and any number bigger than 3 if you multiply it with 4 and solve the equation, your answer would be reasonable
It’s that last one 8 square root 10^3x
You split the figure into 2 pieces; then what you would do is just find the surface area or volume of the 2 separate figures and add them together! Hoped this helped!