Final answer:
According to Kohlberg's theory of moral development, Maria's husband is demonstrating the conventional level of moral development by adhering strictly to the traffic laws.
Step-by-step explanation:
Maria's husband's statement that he will not drive faster than the posted speed limit because responsible, law-abiding citizens should always obey traffic laws is demonstrative of the conventional level of moral development according to Lawrence Kohlberg's theory. At this stage, individuals are conforming to the standards of what is considered 'good' and 'bad' in society, and their behavior is based on an understanding of societal laws and norms. Kohlberg's theory includes three main levels: preconventional, conventional, and postconventional, with the latter representing a higher form of moral reasoning where abstract principles guide decisions, and legality may not always align with morality.