Let P be the relation defined on the set of all real numbers such that $\;P = \{ (a,b) : sec^{2}a - tan^{2} b=1\}$ . Then P is :

Question

(a) reflexive and symmetric but not transitive \[\](b) reflexive and transitive but not symmetric \[\](c) symmetric and transitive but not reflexive \[\](d) an equivalence relation