Which of the following is a true statement regarding community property law?

a$.$ For a married couple living in Wisconsin, income derived from separate property is taxable to the owner of the property.

b$.$ Property acquired before marriage in a community property state becomes community property unless specifically opted out.

c$.$ For a married couple living in California, income derived from separate property produces community income.

d$.$ In all community property states, the salary of married spouses is allocated one$-$half to each spouse.