A standing wave having 3 nodes and 2 antinodes is formed between 1.21Å distance then the wavelength is :

Question

$\begin{array}{1 1} (1)\; 1.21 Å \\ (2)\; 2.42 Å \\ (3)\; 0.605 Å \\ (4)\; 4.84 Å \end{array}$