Which sentence correctly uses a comma despite lacking conjunction?

The sentence that correctly uses a comma despite lacking a conjunction is the one that highlights a separation of ideas related to an emotional response. In this case, the comma is effectively used to clarify the meaning by indicating a pause or shift in thought. The phrasing “not playing a joke” acts as a modifier or an explanation of the sentiment expressed earlier in the sentence, which adds nuance to the emotion of anger. This usage illustrates how a comma can serve to enhance comprehension by separating a contrasting idea without the presence of a conjunction.

In contrast, the other sentences either include conjunctions that make the comma necessary, or they connect statements in a way that does not require a comma at all. Each one demonstrates a different grammatical structure, which serves to reinforce the proper application of punctuation in varying contexts.