The petition shall be filed in any of the following:

1. (a) The county in which a minor described in Chapter 2 (commencing with Section 7820) resides or is found.
2. (b) The county in which any of the acts which are set forth in Chapter 2 (commencing with Section 7820) are alleged to have occurred.
3. (c) The county in which a petition for the adoption of the child has been filed or the adoption agency to which the child has been relinquished or proposed to be relinquished has an office.