In an ideal gas mixture consisting of components \(A\) and \(B\), the mole fraction of component \(A\) is equal to

(a) \(n_{\mathrm{A}}=\frac{p_{\mathrm{A}}+p_{\mathrm{B}}}{P}\)

(b) \(n_{\mathrm{A}}=\frac{p_{\mathrm{A}}-p_{\mathrm{B}}}{P}\)

(c) \(n_{\mathrm{A}}=\frac{P}{p_{\mathrm{A}}+p_{\mathrm{B}}}\)

(d) \(n_{\mathrm{A}}=\frac{P}{p_{\mathrm{A}}-p_{\mathrm{B}}}\).