Which amino acid is a precursor for nitric oxide and may help as a supplement for the metabolically stressed?
a. arginine
b. lysine
c. cysteine
d. tyrosine
e. glutamine
Question 2
How much did spending on prescription drugs increase between the years 1990 and 2011 in the United States?
a. two-fold
b. three-fold
c. four-fold
d. six-fold
e. eight-fold