$\text {Air is flowing straight toward a building. What expression would provide \(\partial p / \partial x\) if \(x\)}$

$\text {Air is flowing straight toward a building. What expression would provide \(\partial p / \partial x\) if \(x\) }$$\text { is measured perpendicular to the building? Neglect viscous and gravity effects and assume}$ $\text {steady flow.}$

A) $\partial p / \partial x = - \rho ( u \partial u / \partial x - v \partial v / \partial y )$
B) $\partial p / \partial x = - \rho u \partial u / \partial x$
C) $\partial p / \partial x = - \rho v \partial u / \partial x$
D) $\partial p / \partial x = - \rho ( u \partial u / \partial x - v \partial u / \partial y )$