A String with Mass Density Equal to 0

Multiple Choice

A string with mass density equal to 0.0025 kg/m is fixed at both ends and at a tension of 290 N.Resonant frequencies are found at 558 Hz and the next one at 744 Hz.What is the fundamental frequency of the string?

A) 558 Hz
B) 372 Hz
C) 93 Hz
D) 186 Hz
E) none of the above