Two Stereo Speakers Mounted 4

Two stereo speakers mounted 4.52 m apart on a wall emit identical sound waves.You are standing at the opposite wall of the room at a point directly between the two speakers.You walk 2.11 m parallel to the wall,to a location where you first notice that the sound intensity is much less.If the wall along which you are walking is 10.7 m from the wall with the speakers,what is the wavelength of the sound waves?

A) 1.71 m
B) 2.05 m
C) 2.57 m
D) 2.91 m