PLZ HELP MEEEE!!! In this excerpt, which word or phrase makes the transition from one idea to another?

Read the excerpt from The Land by Mildred Taylor.

Hammond and George were all for that. I was too, but Robert held back. He'd had enough of horses for a while. He said he'd rather wait at the finish line to see the horses come in. Although I wanted to ride the course along with my daddy, George, and Hammond, I stayed behind with Robert.

In this excerpt, which word or phrase makes the transition from one idea to another?

A). I was too
B). a while
C). although
D). I stayed