On January 1, research on hypertension starts with 2,000 30 to 40-year-old males of which 120 are already hypertensive. Those 1880 left are followed-up for 5 years during which time 150 of them developed hypertension. Calculate the prevalence of hypertension at the start of the research. Which of the following is the BEST answer: O 6.00% 6.00 0.06 on January 1 O 6.00 on January 1