Assume each instruction on a hypothetical computer executes in three equal stages. When a program with exactly $4$ instructions is executed on a CPU with a three stage pipeline, the execution time of this program $($in comparison to a non pipelined version$)$ is reduced by:

$($assume no dependencies between instructions$)$

Question $4$ options:

$10\%$

$33\%$

$50\%$

$66\%$