I have the following equation:
Array

in my data I have year and Id

I want to get the within the parameter estimates of the above regression
Which one of the following would be correct and why?

xtreg A L1.A L1.B L1.C yr*, fe or

xtreg A L1.A L1.B L1.C, fe or

xtreg A B C yr*, fe or

xtreg A B C, fe


Can anyone help me? Should I include vce(robust)? If not, why?