[单选题]
The velocity of propagata+e g xhp,-w3r1z p6i y3ir3cfion of a 3nswgoz qj3:ff,97d mjb7hq1transverse wave on a 2.0-m long string fixed at both ends is 200 m/s. Which one of the following is not a resonant frsg, f1qm ob:q7zj3j3 f7whn 9dequency of this string?
A. $25 \; Hz$
B. $50 \; Hz$
C. $100 \; Hz$
D. $200 \; Hz$
