Which of these fits gap 18?

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.
Chills, coughs, and sneezes, _____(17)______ fever, headaches and body aches, that may also include watering red eyes, and running nose making you all confused and tired - that is flu.
Each year, from the months of November to April, is the flu season. Therefore, you ______(18)_____that shot of flu vaccine your doctor gives you by fall.
Taking the vaccine will prevent you from catching flu, and even if you ______(19)_____it, the attack will be mild.

Otherwise, you are bound to be ______(20)______in bed for two weeks without meeting your friends.