What is the equation of the circle in General Form whose center is at ( 3, -4) and a radius of 5 units?
1. x² + y² - 6x + 8y + 50 = 0
2. x² + y² -6x + 8y - 50 = 0
3. x² + y² - 6x + 8y = 0
4. x² + y² + 6x - 8y = 0