Layla needs to solve the quadratic equation x^2+x−6=4. Which statement about how Layla should solve this equation is true?

A: The quadratic formula is a good method because this quadratic equation cannot easily be factored
B: The quadratic formula is not a good method because you can factor the equation since -6 is divisible by 3
C: Layla cannot solve this quadratic equation because it is not set equal to 0
D: The quadratic formula is the only way to solve a quadratic equation