Which of the following statements about caffeine intoxication is true?
a. Doctors recommend that all adults limit their caffeine intake to 250 milligrams per day.
b. The recommended maximum dosage for adolescents is 500 milligrams of caffeine a day.
c. Ingesting 50 milligrams of caffeine may produce caffeine intoxication.
d. It is diagnosed on the basis of five or more specific symptoms.
