Which of the following number is divisible by “7” ?

The number is divisibility by ‘7’ subtract twice of the unit digit from the remaining and check whether it is divisible by 7 or continue the above process till you get a simple number.

Option 4, 2401

$\begin{array}{l}240-1\times 2=238\\ 23-8\times 2=7\end{array}$

The number 2401 is divisible by 7