One of the Harmonics of a Column of Air in a Tube

Multiple Choice

One of the harmonics of a column of air in a tube that is open at one end and closed at the other has a frequency of 448 Hz,and the next higher harmonic has a frequency of 576 Hz.How long is the tube? The speed of sound in air is 343 m/s.

A) 1.34 m
B) 0.670 m
C) 0.335 m
D) 1.00 m
E) 2.68 m