Statement 'a' is correct: Some democratic countries are republics. A republic is a state in which supreme power is held by the people and their elected representatives, and which has an elected or nominated president rather than a monarch. Examples include India, the United States, France, Germany, etc., all of which are democratic and republics. Statement 'b' is correct: Some democratic countries are not republics. These are constitutional monarchies, where the monarch is the head of state, but political power is exercised by elected representatives of the people, making the system democratic. Examples include the United Kingdom, Japan, Canada, Australia, etc., which are democratic but have a monarch as head of state and are therefore not republics.