Concept:Ada warns that drug and alcohol abuse can lead to serious mental and physical harm.
Explanation:Ada advises Wanja against going to XYZ Night Club to take marijuana and alcoholic beverages.
She clearly states that people who use hard drugs and alcohol are prone to psychiatric problems or premature death.
The phrase "psychiatric problems" in her admonition points directly to mental illness, such as insanity or madness.
Thus, it can be deduced that taking hard drugs could damage the brain and cause the addict to lose his or her sanity.
The other options are not supported by Ada's words, because she never says drugs will make people adore, respect, or behave courteously toward an addict.
Answer:A. lead to insanity of the addicts.