Answer:
The missing options are:
a) Ginseng
b) Valerian
c) Licorice
d) Feverfew
The answer is b) Valerian.
Step-by-step explanation:
Ginseng is used to prevent loss of memory. Licorice is used to stop coughing and as a disinfectant. Feverfew is used to help with headaches. Valerian is used to helping with sleep, shortening the length of time it takes to fall asleep and decreasing the number of nightmare awakenings due to its anxiolytic and sedative properties.