[单选题]
Figure 11-2 is a "sn cyidtqp50.a)e anc9ai9t 8y; ko*: bcswl-lvnn,1lg mjfny re)s2b: 9+l6 b8apshot" of a wave at a given time. The frequency of the wave is 120 Hz,9g- onl 1m8b2rsl:* e+lyc w:snbn)fbkj6 vl. What is the amplitude?
A. $0.05 \; m$
B. $0.10 \; m$
C. $0.15 \; m$
D. $0.20 \; m$
