What should be the $pOH$ of a basic solution ?

The correct option is B $<7$

The $pOH$ scale is similar to the $pH$ scale. Solution with $pOH$ of 7 is the indicative of a neutral solution. So , when the value of $pOH$ is greater than 7 , then it will come into acidic range and when the $pOH$ is less than 7 , then the solution will come in basic range.
As here the solution is basic So , its $pOH$ should be $<7$.