We can use singular or plural verbs with many collective nouns, Pamela, and government is one of these. 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.
family / team / committee / firm
Collective nouns refer to groups of people usually. Our choice of singular or plural verb form often depends on whether we are thinking of the group as an impersonal unit (in which case we use the singular verb - and relative pronoun which) or as a collection of individuals (in which case we use the plural verb form - and relative pronoun who). Compare the following:
the UN / New Labour / the BBC
My family, who have lived on this island all their lives, are determined to remain here.
The team who are playing this weekend includes neither of the new signings. The team which lies third from the bottom of the league will also be relegated this year.
The human resources committee is going to meet on Thursday. They will endorse all promotions from grade C to grade B for the coming year.
My firm, which was established in 1932, has been manufacturing motor mowers since the 1950s. They look after me very well and have an excellent pension scheme.
Corporate bodies like those above also fall into the above category:
people / police / cattle
The UN says it has no plans to move a further detachment of troops to the war-torn area. But in effect they are in disagreement on this issue.
New Labour is holding its annual conference in Brighton this week. They plan to discuss international issues as well as local concerns.
The BBC has appointed Mark Damazer as its controller of Radio 4. Many staff were surprised by the appointment.
These collective nouns always take a plural verb. There is no singular form of these nouns:
the rich / the poor / the homeless
People who have invested all their savings in shares are sure to lose out.
Police in this area are currently investigating 74 allegations of date rape.
All the cattle were moved to the fields lower down the valley as winter approached.
Note that when adjectives are used as collective nouns they always accompanied by a plural verb form:
a / each / every / this / that team
The rich tend to reside in the outer suburbs whilst the poor are confined to the inner city areas in this country.
The homeless are well looked after at Christmas in Britain when they are offered shelter, food and hot showers.
Note that when collective nouns are used with singular determiners, such as those above, singular verbs and pronouns are the norm:
That team is capable of winning all the major trophies this year.
A team of inspectors from Scotland Yard is visiting the island this week.
Every family that receives income support will be means-tested.
A government which fails to honour its promises should not be re-elected.