A non-optional social convention refers to a customary practice or behavior that is expected or required in a particular society or culture. These conventions are not optional and are considered necessary for individuals to adhere to in order to be accepted or respected within that social group. Failure to comply with these conventions may result in social consequences or ostracization. Examples of non-optional social conventions include greeting someone with a handshake or bowing in certain cultures, or following specific dress codes for formal events. **

Yes, dual citizenship is optional in many countries. Some countries allow individuals to hold citizenship in more than one country, while others do not. It is important to check the laws and regulations of each country to determine if dual citizenship is allowed and what the requirements are for obtaining it. Additionally, some countries may have restrictions on dual citizenship, such as requiring individuals to renounce their citizenship in one country in order to become a citizen of another. **

Optional means that something is not required or mandatory. It is up to the individual's discretion whether to choose or use it. In other words, it is something that can be done or used if desired, but is not necessary. **

Wearing a tie is often considered a formal or professional dress code requirement in many settings such as business meetings, interviews, or formal events. However, in more casual or relaxed environments, wearing a tie may be optional. It ultimately depends on the specific dress code of the event or workplace. **

Prison food is not always optional for inmates. In many cases, prisoners are required to eat the meals provided by the prison facility. However, some prisons may offer alternative options for inmates with dietary restrictions or religious dietary requirements. Overall, the availability of optional food choices in prison can vary depending on the specific policies of the facility. **

The opposite of optional is mandatory. When something is mandatory, it is required or obligatory, meaning it must be done or used. This is in contrast to something that is optional, which is not required and can be chosen or omitted. **

Yes, the English book club is optional. It is not mandatory for students to participate in the book club, but it is available for those who are interested in reading and discussing English literature with their peers. Students can choose to join the book club based on their own interests and availability. **

Optional updates can be installed by accessing the Windows Update settings on your computer. You can do this by clicking on the Start button, then selecting Settings > Update & Security > Windows Update. From there, you can click on the "Check for updates" button to see if any optional updates are available. If there are optional updates, you can select them and click on the "Download and install" button to install them on your computer. **