Based on the given options, the statement that best reflects how the platform reflected the regional politics of the era is:
"It represented increased sectionalism."
The platform referred to here is not specified, so it is difficult to provide a specific answer. However, if the platform being referred to is associated with the era of increased sectionalism, it would suggest that the platform reflected the growing divide and tensions between different regions of the country, particularly between the North and the South. This is in line with the concept of increased sectionalism during that time period, where regional differences, particularly over issues such as slavery, were becoming more pronounced and divisive.