The answer is The levels of G1 cyclins are too low.
Not exactly sure but your teeth and saliva break down food before it becomes further broken down in the stomach(churning action and the stomach acid) it then passes to the small intestines as chyme. So with process of elimination it is definitely not C or D. So it is up to you to decide what counts as digesting. It is either A or B even though in real life both make sense
They are asking you to do physical Leg Stretches and record the time you spent doing that into your fitness log.
It could be drugs and/or unsafe sex