The body has been knit to the length specified in the pattern, and has been set aside until the next part is complete. I’ve just cast on for the first sleeve and begun knitting it. I originally thought I’d use the same needle for the ribbing as I did in the body (10.5 US). However, when I had cast on and knit for several rounds, it looked far too large. So I found my needles that the pattern recommended (9 US), and cast on again with those. It looks much, much better.
The reason I did not knit the body ribbing on smaller needles is that I didn’t want it cinching in at the bottom of the cardigan. I still am very happy with that decision. So now I need to knit two sleeves to a certain point before joining everything together to continue on.