Step 1: Pick out the country clues:
The question is about Britain only. Each wrong option points to some other country or to the opposite of a movement's goal.
Step 2: Reservation:
Reservation in government jobs belongs to the Indian system, so it is not a British outcome.
Step 3: Coloured people:
Positive affirmation for coloured people points to the American civil rights movement, so it is out.
Step 4: Monarchy:
Social movements pushed Britain towards democracy and away from royal privilege. Protecting royal prestige does not fit a movement outcome.
Step 5: Voting rights:
Mass campaigns over many years gave every adult citizen the vote in Britain. This leaves option 4 as the answer.
Step 6: Quick recap:
A quick memory aid helps here. Britain gave the world early campaigns for the vote, from the Chartists to the suffragettes, and the result was a vote for every adult. Reservation and affirmative action are tied to India and the United States, and royal prestige is not a movement outcome.
Step 7: Final Answer:
Universal adult suffrage is the British outcome.
\[ \boxed{\text{Option 4}} \]