The correct option is B Good placements are guaranteed by our courses.
<!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}-->
The correct answer is ‘Good placements are guaranteed by our courses.’ In the given sentence, the focus is on the doer, ‘our courses’ because here the doer is actively performing the action on ‘the receiver’, good placements. When we change the sentence into passive voice, the focus shifts from ‘the doer’ of the action to ‘the receiver’ of the action, that is, ’good placements.’