13)ANSWER C  "Dimetane-DC is an opioid antitussive that contains codeine."

Explanation

Dimetane-DC is an opioid antitussive that contains codeine, affecting the cough center directly and suppressing the central nervous system. Dextromethorphan is a nonopioid antitussive that suppresses the cough reflex directly by affecting the cough center. Recall the difference between the letters DM and DC after a medication. DC would indicate that codeine is in the medication. Use of this knowledge will lead to the only correct option, 4. DM after a medication name does not refer to a narcotic in the medication. This will allow you to eliminate the other three options.