What is the Brønsted–Lowry conjugate base of \({{\text{H}}_{\text{2}}}{\text{PO}}_4^ - \)?

A.     \({{\text{H}}_{\text{3}}}{\text{P}}{{\text{O}}_{\text{4}}}\)

B.     \({\text{HPO}}_4^{2 - }\)

C.     \({\text{PO}}_4^{3 - }\)

D.     \({\text{H}}{{\text{O}}^ - }\)

B