Final answer:
There is no information indicating that former President Ronald Reagan made changes to the Code of Conduct in March 1988. The details provided cover other aspects of his presidency, including economic and defense policies, but not the Code of Conduct.
Step-by-step explanation:
In March 1988, former President Ronald Reagan did not specifically reform or alter the Code of Conduct. The information provided does not include any actions taken by Reagan in March 1988 regarding the Code of Conduct. Throughout his presidency, Reagan worked to stimulate economic growth and strengthen national defense, but there is no record in the material provided of him making changes to the Code of Conduct at that time. Therefore, the answers provided (a) Abolished it, (b) Strengthened its provisions, (c) Signed it into law, and (d) Made no changes to it, are not supported by the presented facts related to the Code of Conduct in the context of March 1988.
Reagan's presidency did include efforts that had significant impacts on various sectors such as economic policy, national defense, and social issues. For example, he cut taxes, increased employment, and took controversial actions against unions. However, these measures do not pertain directly to the Code of Conduct mentioned in the student's question.