Two Stereo Speakers Mounted 4 $10.7 \mathrm {~m}$ From the Wall with the Speakers, What Is the Wavelength

Multiple Choice

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 essentially zero. If the wall along which you are walking is $10.7 \mathrm {~m}$ from the wall with the speakers, what is the wavelength of the sound waves? The walls are cushioned to absorb sound reflections.

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