Rational numbers are any numbers that terminate (the decimal ends somewhere)
The only set that does this is D, since

All other sets have these:

None of these terminate (the decimals goes on forever), so the answer is D
Answer:
A
Step-by-step explanation:
We Know, 1 Km = 1000 m
so, 2 Km = 2000 m
So, ratio would be: 500 m / 2000 m
ratio = 1/4
So, your final answer is 1:4
Hope this helps!
I think it’s increasing i’m not sure though