Which of these is a requirement for claiming the California Joint Custody Head of Household Credit?

$1.$

$$A verbal custody agreement between the parents.

$2.$

The home must be the home of the taxpayer's child, stepchild, or grandchild for at least half of the tax year.

$3.$

The taxpayer must be separated or divorced for at least six months.

$4.$

The taxpayer must file as single or married

$/$

RDP filing separately.