The answer to your question depends on how "original work" is defined in the context in which you are asking.
a. Yes, because you rephrased it. - If the emphasis is on the effort of rephrasing and creating a new version of the content, one might argue that this constitutes original work.
b. No, the ideas are not your own. - If original work is defined as presenting one's own ideas and not merely rephrasing someone else's concepts, then this response is valid.
In most academic and ethical contexts, the better answer is b, as original work typically requires original ideas and insights, not just reworded content.