Solution:
The correct option is
(A) The square of every real number is positive
Square of every real number is positive, as multiplying negative number two times we get positive number and multiplication of positive number is always positive.
Therefore, there does not exist any real number whose square is negative.
So, and are incorrect.
And (A) is correct.
is an irrational number as it can’t be represented in the form of , where and both are integers.
Therefore, D is also incorrect.
As a result, only A is true.