Step 1: Understand the question.
The question asks what the programme Nationwide was about.
Step 2: Recall what the passage says.
The passage says the groups watched an episode of Nationwide, a British news magazine show, which looked at the economic effects of the government's yearly budget on three families.
Step 3: Check option 1, Planning annual budget for families.
The programme did not teach families how to plan a budget. It reported on the government budget, so this is wrong. So option 1 is wrong.
Step 4: Check option 2, Life challenges of three families.
The three families appear in the episode, but their life challenges are not the theme. The theme is the budget effect on them. So option 2 is wrong.
Step 5: Check option 3, Government development policies on families.
Development policies are not mentioned. The topic was the annual budget, so this is wrong. So option 3 is wrong.
Step 6: Check option 4, Economic consequences of government's annual budget on three families.
This repeats the passage closely: the economic consequences of the annual government budget on three families. This is right. So option 4 is right.
Final Answer:
The episode assessed the economic consequences of the annual budget on three families, which is option 4.
\[ \boxed{\text{Option 4}} \]