In the expression \(2r + 3t + s + 1\), the terms are the individual components that are added together. The terms in this expression are:
- \(2r\)
- \(3t\)
- \(s\)
- \(1\)
So, all of the options provided are terms in the expression:
- \(s\)
- \(1\)
- \(2r\)
- \(3t\)