This question revolves around the treatment of mechanical aspects of writing in the initial stage. The correct answer, D, is supported by the text, which states that grammar, punctuation, and spelling can wait until the revision stage. Option A is incorrect because the text suggests that the focus should be on idea expression. Option B is wrong because it suggests ignoring these aspects entirely, which is not advisable. Option C is incorrect because it suggests immediate attention to mechanics, which is not the text's recommendation.