The conclusion doesn't assert any causal relationship. The author claims that the first economies were barter-based, not that barter caused anything to happen.

The premises don't contradict each other. It's perfectly consistent for an isolated economy to revert to barter when currency disappears and then switch back to currency when it becomes available again. Those two facts describe different moments in time and fit together without any conflict.

The conclusion doesn't recommend or prescribe anything. The author never says we should use barter, or that barter is better than money, or that anything ought to be done at all. The conclusion is purely descriptive: the first economies were barter-based.

You might be drawn to (D) because the argument does involve a claim about historical ordering: barter came first, money came later. So "one event occurred before the other" sounds like it fits. But (D) describes a specific flaw where someone sees that A happened before B and then incorrectly concludes that A caused B. That's not what happens here. The author never claims barter caused money to develop. The argument's flaw is circularity, not a confusion between sequence and causation.

This accurately describes the circular reasoning. The premise describes economies reverting to "the original barter system," which presupposes that barter was the original economic system. But proving that barter was the original economic system is exactly what the conclusion is trying to do. So the premise can be persuasive support for the conclusion only if you already accept the conclusion. That's what it means for a premise to "presuppose what the argument attempts to show."