# Let S1, S2 and S3 be three sets defined as S1 = {z ∈ C : |z - 1| ≤ √2}

Let S1, S2 and S3 be three sets defined as

$$S_1=\{z \in \mathbb C:|z-1|\leq \sqrt{2}\}$$

$$S_2=\{z \in \mathbb C:\text{Re} \big((1-i)z\big)\geq 1\}$$

$$S_3=\{z \in \mathbb C:\text{Im}(z)\leq 1\}$$

Then the set $$S_1\cap S_2\cap S_3$$

(1) Is a singleton

(2) Has exactly two elements

(3) Has infinitely many elements

(4) Has exactly three elements