Question

What is the BEST way to combine the information in the two clauses below?

Meilin was the class treasurer. She is running for student council president this year.
Meilin, the former class treasurer, is running for student council president this year.
Meilin was the class treasurer; is running for student council president this year.
Meilin is running for student council president this year, but was the class treasurer.
Meilin is running for student council president this year, Meilin was the class treasurer.