B
Explanation:
A standing wave is the superposition of two waves which produces a wave that varies in amplitude but does not propagate. Nodes are points of no motion in standing waves. An antinode is the location of maximum amplitude of a standing wave. Normal modes of a wave on a string are the possible standing wave patterns.
The highest point on a wave is called the peak Β
The lowest point is called the trough
The part of the wave half way in between the peak and the trough is called the baseline.