Final answer:
The correct punctuation choice in the given sentences is using a semicolon to separate the two independent clauses.
Step-by-step explanation:
The correctly punctuated sentence is B. David was not an angel; he was always getting in trouble with his teachers.
This sentence uses a semicolon (;) to separate the two independent clauses 'David was not an angel' and 'he was always getting in trouble with his teachers'. This punctuation choice is appropriate because both clauses are closely related in meaning. Option A is incorrect because it uses a period, which creates two separate sentences. Option C is incorrect because it uses a comma without a coordinating conjunction, which creates a comma splice.
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