Which complex number will be located above the real axis and to the left of the imaginary axis?

a) 4i
b) 2-4i
c) 4i-1
d) -1-2i

For this case the first thing we should know is that a complex number is a number of the form:
 a + bi
 Where,
 a: real part
 bi: imaginary part
 The real part is represented on the horizontal axis of the complex plane
 The imaginary part is represented on the vertical axis of the complex plane
 We are looking for a unique number is:
 above the real axis and to the left of the imaginary axis
 Equivalently:
 Second quadrant of the complex plane.
 Using the definition, the number that complies with this feature is:
 4i-1
 
 c) 4i-1