Answer:
None of the above
Explanation:
To be an irrational number it has to be non repeating and non terminating which means none of these could be an irrational number.
0.636363.. is non terminating but it is repeating the same 2 numbers so therefore it is a rational number
6 is a terminating number which makes it rational
25 is a terminating number which makes it rational
0.45 is terminating number which makes it also a rational number
therefore there are no irrational numbers in this problem