Mathematics for IGCSE & O level - Using A Calculator (Section 3 - No. 4)

What is the name of the formula for the surface area of a sphere?

$$ A = 4pi r^2 $$

$$ A = 2pi r $$

$$ A = pi r^2 $$

None of the above

The correct formula is $$ A = 4pi r^2 $$.