[单选题]
A wave moves on a string with wavduwsisq s84er at 3)(2elength l and frequency qgqjr:1e6 (cuf. A second wave on the same string has wavelength qqg (6 1j:recu2l and travels with the same velocity. What is the frequency of the second wave?
A. $0.5 \; f$
B. $f$
C. $2 \; f$
D. It cannot be determined from the information given.
