Consider the set of points S={z∈C:∣z−3∣=∣z+3i∣}S = \{z \in \mathbb{C} : |z - 3| = |z + 3i|\}S={z∈C:∣z−3∣=∣z+3i∣}. Which geometric shape describes this set?
A circle centered at the origin with radius 3
A straight line with equation y=xy = xy=x
A straight line with equation y=−xy = -xy=−x
A hyperbola with foci at 333 and −3i-3i−3i