Opportunity cost refers to what you have to give up to buy what you want in terms of other goods or services. When economists use the word “cost,” we usually mean opportunity cost.
Answer:

Explanation:
As we know that the orbital speed of the satellite is given as

also we know that
time period of the revolution is given as

now from above equation we know that


so we will have

now plug in all data in this equation


Sewage. If thats not it, then I need to see your choices. :)
A rain gauge! Hope this helps!