Standing Waves on a String: Two Violinists Are Trying to Tune

Multiple Choice

Standing waves on a string: Two violinists are trying to tune their instruments in an orchestra. One is producing the desired frequency of 440.0 Hz. The other is producing a frequency of 448.4 Hz. By what percentage should the out-of-tune musician change the tension in his string to bring his instrument into tune at 440.0 Hz?

A) +1.9%
B) -1.9%
C) +3.7%
D) -3.7%
E) +8.4%