Which of the following additional facts will best strengthen the conclusion that consent to search, if given, was voluntary?

Also, explain the argument, justify the answer.

1. Marcella was informed of her right to refuse consent.
2. Marcella was a college graduate.
3. The encounter took place in a well-lighted, public area with other persons present.
4. Only one officer was present when the request to search was made.
5. The police and Marcella were all the same race and ethnic background.