About a GRE question of Squares and Exponents(Please give answer with nice and helpful explaination).?

Column A: Column B:

sqrt(1/4^2) 1/4

Option A: Quantity A is greater

Option B: Quantity B is greater

Option C: Both quantities are equal

Option D: Relationship cannot be determined

I thought that squr(1/4^2) should be +1/4 or -1/4 because both can yield the same answer so I ticked the answer option D the relationship cannot be determined.

But the solution shows that Option C is correct answer means the answer of column A is 1/4 and column B is also 1/4.

Now my confusion is whether I am right or wrong about my first answer and also please give me suggestions about if I am right then do I only have to follow the +1/4 answer for GRE exams?