Select the incorrect statement.
a. sympathomimetics in otc cold products can cause jitters and insomnia, like caffeine can.
b. psychological dependence on caffeine is usually minor.
c. caffeine has been proven to cause cancers of the bladder, colon, and kidneys.
d. the symptoms of caffeinism include agitation, tremors, and insomnia.

C. Caffeine has been proven to cause cancers of the bladder, colon, and kidneys.

Explanation:

Caffeine effects include increased wakefulness and alertness, provide a feeling of well-being and decreased fatigue. In addition to these effects it may lead to undesirable effects such as increased gastric secretion, increased gastroesophageal reflux, risk of miscarriage, may lead to feelings of anxiety, distress and sleep changes. However, let us not forget that recent research has shown that caffeine can cause bladder, colon and kidney cancer.