For All the Allowed Vibration(s) (Wavelength(s)) of a Plucked Guitar

Multiple Choice

For all the allowed vibration(s) (wavelength(s) ) of a plucked guitar string, what is the correct relationship between the length of the string, L, and the wavelength, ?

A) L = /2
B) L = 
C) L = n/2 where n is a positive integer
D) L = n where n is a positive integer
E) L = 1/