wave is controlled by
Solving question posted in image for you:
By definition, the node is the point along the standing wave where the amplitude is minimum. Thus the strain is maximum at the nodes in such waves.
At the antinode of a stationary waves, the amplitude is the largest.
However, the density remains constant at antinodes as the concentration of particles at the antinodes is constant. This also mean that the pressure is constant.
Thus, No strain is experienced at antinodes in a stationary wave.
So correct option is 4.