Answer:
Option B, z = 2
Step-by-step explanation:
Step 1: Factor
z^2 - 4z + 4 = 0
(z - 2)(z - 2) = 0
Step 2: Solve for z
z - 2 + 2 = 0 + 2 and z - 2 + 2 = 0 + 2
z = 2 and z = 2
Double root at z = 2
Answer: Option B, z = 2
