Answer:
The concept of "proof points" that McDonald's uses to bolster its claims about its food is similar to what the text describes as a support statement.
The concept of "proof points" implies a marketing technique used by McDonald's against its competitors, through which it seeks to change the preferences of consumers over their products through data (which is intended to be objective but mostly is not) that reinforce and support their claims of leadership and excellence of their products. Thus, the proof points allow to show the consumer the quality of the product, looking for the consumer to prefer the McDonald's brand over any other competitor.
For example, if McDonald's claims that its vegetables are grown without preservatives, a proof point could be a campaign of tours to the company's farms or an advertisement that shows a certification for this purpose.