Longitudional waves travel through a series of and

a. compressions; rarefactions
b. oscillations; propagations
c. destructions; constructions
d. disturbances; oscillations

A. compressions; rarefactions

Explanation:

As we know that we have two type of travelling wave as per propagation of wave

1) Transverse wave

2) Longitudinal wave

In transverse waves we know that medium particles will move to and from in perpendicular direction of propagation of wave

while in case of longitudinal wave we know that particles will move to and fro in the direction of propagation of wave itself

so here correct answer will be

A. compressions; rarefactions

a displacement distance is size of displ

the area between the graph and the t axis