Alejandro is a resident of New Mexico, and his wife Maria is domiciled in and a resident of California. Alejandro earned $60,000, and Maria earned $42,000 in 2017. (Note: All income was from wages.) They filed a joint federal return. Which of the following is correct?

A. Maria may file a California return using "married filing separately" and report only her $42,000 California wages.

B. They must file a joint California return using Form 540NR and pay tax only on Maria's $42,000 California-source income.

C. They must file a joint California return using Form 540NR and pay tax on all of Maria's and Alejandro's income.

D. They may file a joint California return using Form 540NR and pay tax on $72,000 income ($42,000 California-source wages and $30,000 of Alejandro's wages).