I need help on this question ( Please show all work and explain clearly )

Answer:
C
Step-by-step explanation:
The area (A) of a circle is calculated as
A = πr² ( where r is the radius )
Here diameter = 8 cm , thus r = 8 ÷ 2 = 4 cm , thus
A = π × 4² = 16π cm² → C
Answer:
C
Step-by-step explanation:
The equation of the area of a circle is [tex]\pi r^{2}[/tex].
We already know the diameter is 8, and the radius is half of the diameter, so it would be 4.
[tex]\pi 4^{2}[/tex]. This is our equation now. Now, we need to square 4, and 4x4 is 16.
Since 16[tex]\pi[/tex] and [tex]\pi[/tex]16 are the same, C is the correct answer.