Which of the following is one of the four categories of harmful consequences that suggest substance abuse?
a. The individual fails to fulfill important obligations at work, home, or school as a result of substance use.
b. The individual stops using the substance because of legal problems in the past.
c. The individual uses the substance only in situations in which it is not physically hazardous to do so.
d. The individual complains of withdrawal symptoms, such as nervousness, headaches, and nausea.