[单选题]
A string of linear density 1.5 g(hqxdl0+o.o7wh juwu 3. 9 fne/m is under a tension of 20 N. What shoul5v-c:/ufnuj/+ue kn ep ,8zl yz:opw0d its length be if its fundamentn +e,luc f:ze5wy8: 0n zvo/jpup-k/ual resonance frequency is 220 Hz?
A. $0.26 \; m$
B. $0.96 \; m$
C. $1.1 \; m$
D. $1.2 \; m$
