Answer:
D. place where a standing wave remains fixed in space.
Step-by-step explanation:
A node is point where the amplitude of wave will be zero.But on the other hand a point where amplitude of wave is maximum is called anti node .When two wave superimpose then they form node and anti node continuously.
So we can say that ,a node is a place where a standing wave remains fixed in space.Stationary wave is called standing wave.