The answer would be 7
because the square root of 49 is 7.
so 7 multiplied 7 is ..49
The answer wont be -7 because in Principal root,
negative numbers are not involved, you cant do it! :)
That being said you'd also be able to know that since no negative numbers are allowed in principle root, -7 and 7 are out as choices, and D is totally wrong since we now know what the priniciple root means :)
The answer is 7
Hope this helped !