Final answer:
The sentence that is punctuated correctly is: 'I am planning on going to my English class today, but I'm not prepared for the test.'
Step-by-step explanation:
The sentence that is punctuated correctly is:
I am planning on going to my English class today, but I'm not prepared for the test.
In this sentence, the comma is used correctly to separate the two independent clauses: 'I am planning on going to my English class today' and 'I'm not prepared for the test.'
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