若曲線y=2sin(x+)cos(x-)和直線y=在y軸右側(cè)的交點(diǎn)按橫坐標(biāo)從小到大的順序依次記為P₁、P₂、P₃、…,則|P₂P₄|等于(    )

A.π                B.2π                    C.3π                    D.4π