"…But God is uncaused, as shown above, since He is the first efficient cause."I should point out again, that while Aquinas identifies the first cause as God, I'm not accepting that as a requirement in this discussion, call it what you wish. I'm using the generic for "first cause argument" and including Aquinas' work and others on both the argument and objections.
I was asking for A’s exact wording of his premise.