Define a relation R on the interval $$[0,\frac{\pi}{2})$$ by $$xRy$$ if and only if$$\sec^{2} x-\tan^{2} y=1$$. Then R is :

A

both reflexive and transitive but not symmetric

B

an equivalence relation

C

reflexive but neither symmetric not transitive

D

both reflexive and symmetric but not transitive