is an SD for a year-long course possible or do I just need to ask for an extension?

I'm in a year-long history course and need more time to complete some work due to health/compassionate reasons but I'm not sure if I should ask for an SD on the concession form since it's a year-long course. Since I'm not going home or working during the holiday break I could finish the term 1 work before term 2 starts so I guess technically an extension is more appropriate? I appreciate any input yall got in these confusing mf times