Primarily because of its importance in the spread of ideas and investigating candidates’ claims, which of the freedoms listed below is critical to ensure fair elections?

Based on the information provided, it seems like the answer would be the freedom of the press.

The freedom of the press is a 1st amendment right that allows investigative journalists to spread information to the public about candidates and their policies. The ability to share this information without the threat of persecution is a critical element of having a fair election. The citizens should have all the information about a candidates policies/programs in order to make an educated decision as to who would be the best person for the job.