McDonald$$s introduced a Favorites Under $400$ Calorie Menu as part of an attempt to reverse the perception that McDonald$$s sells only unhealthy food. Suppose that McDonald$$s$,$ as a follow$-$up$,$ collects and analyzes social media posts from Facebook, Twitter, and similar sites, hoping to understand whether or not consumer perceptions are improving. This would be an example of:

Multiple Choice

neuromarketing.

an online focus group.

sentiment mining.

quantitative research.

an experiment.