<em>C.) We all had tears in our eyes, as he spoke.</em>
Explanation:
A comma joins two independent clauses. The clause 'We all had tears in our eyes' is indeed independent, while the fragment 'as he spoke' is not -- meaning it cannot be it's own sentence/phrase.
This sentence in particular does not need a comma to join the independent and dependent clauses, nor does require a pause in between words.
