The correct answer is Xylitol.

- Xylitol is a sugar alcohol widely used as an anti-cariogenic agent because it exerts its effect primarily by inhibiting bacterial glycolysis.
- When oral bacteria such as *Streptococcus mutans* take up xylitol, they are unable to metabolize it properly.
- This disrupts their energy production by inhibiting the glycolytic pathway, leading to reduced acid production in dental plaque.
- Since acid production by bacteria is a crucial factor in the development of dental caries, xylitol helps reduce caries risk by lowering acid production and bacterial growth.

In contrast:
- Chlorhexidine is an antimicrobial agent that kills bacteria primarily by disrupting bacterial cell membranes.
- Fluoride helps in remineralization of enamel and inhibits bacterial metabolism but primarily acts by promoting enamel resistance to acid demineralization.
- Sodium lauryl sulfate is a detergent used in toothpaste for foam generation and plaque removal but does not have a specific anti-glycolytic effect.

Thus, the primary mechanism by which xylitol reduces cariogenic potential is through inhibition of bacterial glycolysis and acid production.

Reference: Ten Cate's Oral Histology, 9th Edition, Chapter 6 - Dental Caries, p. 150-155