How does setting a specific time-frame in which to complete a goal increase the chances of the goal being met?

a.
it creates accountability by establishing deadlines.
b.
it allows a goal-setter to say "i'll reach that goal when i get to it."
c.
it allows a goal-setter to establish unrealistic goals.
d.
it does not allow short-term goals to feed into a larger goal.

Insulin is a peptide therapeutic used to manage type 1 diabetes, which affects more than 20 million people worldwide according to the international diabetes federation. a significant limitation to the broad distribution and use of insulin to treat type 1 diabetes is the fact that it must be administered by injection rather than orally. why is insulin administered by injection and not orally?