The answer is 72 (--> second choice).
I can prove it without calculator so you believe me:

To order these from the least to greatest you need to convert them all to one common unit of measurement. In this case I chose feet.
385 km= 1, 263, 123 ft
2, 521, 728 in= 210, 144 ft
161, 920 yards= 485, 760 ft
And of course 446, 831 feet equals itself. Now all you have to do is put them in the correct order!
Hope this helped :)
Answer:
4√5
Step-by-step explanation:
Let's call it x
According to Euclidean theorem x^2 = 5×16
x^2= 80 and
x = 4√5