This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to administer flonase
Shake the bottle before removing the cap.
A gentle, side-to-side shake is all that is needed. Once you have shaken the bottle, remove the green cap on top of the bottle.

Select from:
[a]. Shake the bottle for about 30 seconds to a minute before removing the cap. Alternatively, you can actually shake the liquid under the cap, rather than shaking it from the left side..
[b]. Your whole shake should now shake as one fluid measure. Fill a glass with water if you do not have access to a dehumidifier..
[c]. Prime the spray when you first open it or after 7 days of no use. Priming the spray in the bottle helps ensure that the medicine flows freely..
[d]. Insert a cotton ball between the cap and skin. Like tea, you will want to avoid pressing down on the bottle..
The answer is:
[c].