Answer:
The correct option is A) 
Step-by-step explanation:
Consider the provided numbers.
, 0.25,
and 
We need to find which of them is not rational number.
Rational number: A number
is said to be rational, if it is in the form
of p/q. Where p and q are integer and
denominator is not equal to 0. The decimal expansion of rational numbers may terminate or become periodic.
Now convert each of the number in decimal form as shown,
,
Here the decimal expansion of the number is neither terminating nor repeating so it is not a rational number.
0.25,
The decimal expansion of the number is terminating, so it is a rational number.

The decimal expansion of the number is terminating, so it is a rational number.

3 is a rational number.
Hence, the correct option is A) 