The correct options are
A The government passing an Act making it illegal to vote for any competing party
B The governemnt removing names of supporters of other parties from the electoral rolls
C The government banning the formation of any new political party
The government can manipulate the election process in many ways. Some could be direct bans, like in the case of situation 1 and 2. It could reject the candidature of the opposition parties. It can even remove the names of the supporters of opposing parties from electoral rolls. In any of these cases, elections would not be considered 'free and fair'. However, campaigns are a normal part of the election process, and they are often monitored by an independent body to minimise the possibility of manipulation and fraud.