Concept: The question tests on the basic understanding in Algebra.


St(1):- Only gives information about r and nothing


St(2):-R can be +2 or a -2 and then the distance from t would be 4 which is r^2 (=>multiple values of t for same statement=>Insufficient)

Combining both,


|r-t| = r^2 

=> r-t = r^2                    or        r-t = -  (r^2)

=>t = r - r^2                 or          t = r + (r^2)

lets take r = -1/2

=> r^2 = 1/4

=> t = (-1/2) - (1/4) = -(3/4)          or    t =  (-1/2) + (1/4)  = -(1/4)

(Sufficient)  

(option c)