Which parameters must be URLs formatted correctly to ensure proper tracking in Google Analytics?

The correct answer is one that utilizes the proper formatting for URL parameters in Google Analytics. In this case, the URL with "utm_campaign=fallsale" follows the established conventions for URL structure.

In URLs, parameters should not have spaces and must be concatenated with an equals sign without intervening spaces. The underscore used in "fall_sale" is valid in certain contexts, but it is not the standard convention for UTM parameters, which typically use hyphens or are written in a combined format without underscores.

Other options demonstrate incorrect formatting by either including spaces around the equals sign, using underscores, or adding unnecessary spaces, which can lead to tracking issues or misreporting of campaign data. It is essential to ensure parameters are clean and properly formatted to enable accurate tracking and a reliable understanding of campaign performance in Google Analytics.