What is the de Broglie wavelength of a nitrogen molecule in air at $300\; K?$ Assume molecule is moving with the rms speed of molecules at this temp. At. mass of $N= 14.0076 \; u$

Question

$\begin {array} {1 1} (a)\;028 \times 10^9\:m & \quad (b)\;0.0028\: nm \\ (c)\;0.028 \times 10^{-9}\: m & \quad (d)\;2.8\: nm \end {array}$