Which of the following sentences has the correct verb tense?

A、The method we use is interview and survey. We found that most people voted for the candidate whose name is familiar, regardless of the candidate’s political leanings.;
B、The method we use is interview and survey. Our findings indicated that people vote for the candidate whose name is familiar, regardless of the candidate's political leanings.;
C、The method we used was interview and survey. We found that most people voted for the candidate whose name was familiar, regardless of the candidate's political leanings.;
D、The method we use was interview and survey. We found that most people vote for the candidate whose name was familiar, regardless of the candidate's political leanings.