Which sentence is written correctly?

The correct sentence is 'Because she was uncertain of her abilities, Renee asked for help.' This sentence uses a comma after the introductory phrase 'Because she was uncertain of her abilities' to set it off from the main clause 'Renee asked for help.' The comma helps to separate the two parts of the sentence clearly and indicates the pause that should be there when reading it aloud. Options B, C, and D are incorrect because they either use a semicolon incorrectly or have commas placed incorrectly within the sentence.