Hey Ron,
(C) that impose stricter limits on medical services, require doctors to see more patients, and (to)spend
I have a doubt on wrong option C.
As I have indicated above I fell into a trap trying to parallel the part in red above.
Option D instead uses a ing modifier to indicate the second part of what the policy requires of doctors.
My question considering your earlier explanation on page 1 of this thread : Do we push "spend" to an 'ing' modier only because we CANNOT have all the 3 actions here in parallel ? In other words is a change in parallelism must to indicate the specific hierarchy of events in any similar construction ?