Final answer:
One should omit answers on a test only if there is a penalty for wrong guesses, as guessing can be beneficial when there are no penalties for incorrect answers.
Step-by-step explanation:
You should answer all the questions on a test unless B) there is a penalty for wrong guesses. In cases where your score can be negatively impacted by incorrect answers, it is strategically better to omit answers when you're unsure. However, if there is no penalty for guessing, it can be advantageous to make an educated guess. This test-taking strategy is important to consider, especially for standardized tests like the SAT.
While skimming a question can be an effective way to quickly assess what is being asked, you should not omit a question solely because you haven't skimmed it first. Furthermore, the difficulty of a question shouldn't deter you from attempting it, as sometimes questions that seem hard initially can be figured out with some thought. Lastly, having a lucky charm with you during a test might boost your confidence, but it should not influence your decision to leave a question unanswered.