Question

read the source of the allusion.
according to legend, when damocles wished his life were as full of luxuries as that of the tyrant dionysis, dionysis invited damocles to a sumptuous banquet. above damocles seat at the feast, dionysis had placed a sword, suspended only by a thin hair, demonstrating the fragile nature of fortune.
what is the meaning of the allusion in the sentence below?
darnel was enjoying the lush life his newfound riches had brought him, but he couldnt help but think of his latest cholesterol reading as a sword of damocles.
an unhealthy trend
a consequence of overindulgence
a reminder that one is vulnerable

Explanation:

The legend of Damocles shows that fortune is fragile. In the sentence, Darnel's luxurious life (from new - found riches) is juxtaposed with his cholesterol reading. The "Sword of Damocles" here, like in the legend, is a reminder that despite his current enjoyment (luxurious life), there is a threat (high cholesterol) that shows his vulnerability (to health problems that could disrupt his life). It's not about an "unhealthy trend" in a general sense of a pattern over time, nor is it just a "consequence of overindulgence" (though overindulgence might be related to high cholesterol, the main focus of the allusion is on the fragility/vulnerability aspect).

Answer:

a reminder that one is vulnerable