Answer:
I think the answer would be option d.
hope it helps.
D. They all contain carbon as an important part of their structure.
<h2>Frequency</h2>
Explanation:
Wave frequency is the number of waves that pass a fixed point in a given amount of time.
Wave speed is the speed at which a wave travels.
Let the wave speed be 
Let the wave frequency be 
Let the wave length be 
The wave speed,frequency and wave length are related by the equation
.
When
increases,
increases on the other side to maintain equality when no other property is changing.