Final answer:
Currently, d. only males over the age of 18, regardless of citizenship, are required to register for the draft in the U.S. under the Selective Service Act.
Step-by-step explanation:
Based on current law, the group that is required to register for the draft is d) Only males, regardless of citizenship, over the age of 18. The Selective Service System, re-established by Congress in 1940, mandates that all male U.S. citizens and male immigrants, regardless of citizenship status, residing within the United States register within 30 days of their 18th birthday. The Selective Service Act has evolved since its origins in 1917, adapting to the needs and circumstances of the United States over the years, including times of war and peace.
Currently, young men aged between 18 and 25 are expected to register. The act serves as a means to maintain information in case the need for military conscription arises. It is important to note that registering with the Selective Service System is a legal requirement and failure to register can result in penalties. Although women have not been required to register thus far, changes in the law have been discussed, potentially altering this aspect in the future.