The correct similarities between the governments of Brazil and the United States from the provided options would be:
- A president heads the executive branch.
- Each political party selects a presidential candidate before the election.
These points highlight structural similarities in the political systems of both countries. The option stating that "voting is required by law" is true for Brazil but not for the United States. The statement about the judicial branch appointing members to the legislature is not accurate for either country, as the legislature is typically elected by the public.