How much activity should the average adult get each week?

a) at least 2 hours and 30 minutes of aerobic activity at a moderate level or 1 hour and 15 minutes of aerobic activity at a vigorous level, and 2 days of strength training.
b) only 1 day of moderate aerobic activity or 1 day of vigorous aerobic activity, and 3 days of strength training.
c) at least 5 hours of aerobic activity at a moderate level and a vigorous level, and 2 days of strength training to fill a 7 day week
d) only moderate or vigorous level aerobic activity every other day.