∣z∣≥2i.e.,∣z−0∣≥2
∴ The distance of 'z' from origin is greater than two.
We have to find minimum of ∣z+21∣
∣z+21∣=∣z−(−21)∣ = distance of z from (−21,0).
On the argand plane,

z lies in the dotted regions I,II,III,IV.
∴ The minimum distance is from the point B=2−(21)=23
⇒23∈(1,2)