ANSWER: B. Garlic. Researchers from the University of Adelaide (Australia) reported that subjects with high blood pressure taking an aged garlic supplement daily for 12 weeks had a drop in blood pressure that was 10 millimeters of mercury lower than the placebo group. The researchers concluded that the drop in blood pressure from the garlic supplement was likely due to the herb’s ability to boost NO levels. Take 200–1,000 mg of garlic with your preworkout shake. To maintain higher NO levels throughout the day, also consider taking a dose in the morning and later at night.