Citizenship is the status of being a member of a particular country and enjoying the rights and privileges that come with it. In some cases, a person may want to change their citizenship, for example, to become a citizen of another country. This can be done through a process known as renunciation, where the individual formally gives up their citizenship of their current country. This process usually involves filling out specific forms and submitting them to the relevant authorities, and may also involve meeting certain requirements such as residing in the new country for a specific period of time. Therefore, the correct answer is "renunciation".