Singular and plural forms are often mixed as are the pronouns that refer back to the nouns in the previous sentence. So, all four of your options are correct. My family, who have lived on this ...

Eccles, Robert G., Jr. "Price, Authority, and Trust: From Ideal Types to Plural Forms." Annual Review of Sociology 15 (August 1989).

Hong Kong's goal: no accidents on the road. shouldn't the plural form be changed to singular? Hong Kong's goal: zero accident on the road. Hong Kong's goal: no accident on the road. Zero means no ...