A 900-series Social Insurance Number is issued to:

A SIN that begins with “9” (often called a 900-series SIN) is issued to temporary workers—people who are neither Canadian citizens nor permanent residents—and who are authorized to work in Canada. Service Canada’s employer guidance explicitly states that SINs beginning with “9” are issued to temporary workers who are neither Canadian citizens nor permanent residents, and these SINs are valid only until the expiry date shown on the immigration document that authorizes the person to work in Canada.

Service Canada also advises employers to confirm that employees with a SIN starting with “9” remain authorized to work and that their immigration document has not expired.

So, options A–C are incorrect because a 900-series SIN is not for permanent residents (“landed immigrants”), not for Canadians whose SIN “expires,” and not based on working outside Canada. It specifically signals temporary status tied to work authorization in Canada.