Two Sources of Light Illuminate a Double Slit Simultaneously

Multiple Choice

Two sources of light illuminate a double slit simultaneously. One has wavelength 570 nm and the second has an unknown wavelength. The m = 5 bright fringe of the unknown wavelength overlaps the m = 4 bright fringe of the light of 570 nm wavelength. What is the unknown wavelength?

A) 456 nm
B) 326 nm
C) 380 nm
D) 713 nm