An infinite sheet of uniform charge \( \rho_s = 10\, {C/m}^2 \) is placed on the \( z = 0 \) plane. The medium surrounding the sheet has a relative permittivity of 10 . The electric flux density, in C/m\(^2\), at a point \( P(0, 0, 5) \), is: Note: \( \hat{a}, \hat{b}, \hat{c} \) are unit vectors along the \( x, y, z \) directions, respectively.