When the subject needs to be emphasized more than the action performed,the active voice is used.So (a) is correct
If you see someone with a tear in their eye, what do you assume?
Does the tear indicate that they are happy, sad, or indifferent? Choose the answer that is most likely the case.
I’m not sure I quite understand your question. I’d love to help you if only you could just elaborate
Away from the bullet, I would assume...
