Ellen Has Decided to Volunteer for the Democratic Candidate Running

Ellen has decided to volunteer for the Democratic candidate running for president in the upcoming election. Although she is contributing her time as a volunteer to help coordinate and run fundraising events and get-out-the-vote efforts, she has also made financial contributions to the candidate's campaign. What is this an example of?

A) participating in an issue network
B) exercising Fourteenth Amendment rights
C) expressing public opinion
D) petitioning the government