The correct answer is (A) Refraction, dispersion and reflection.
Water droplets refract and disperse sunlight into its colours, then internally reflect it, and refract it again as it exits — forming a rainbow.
Source: Chapter 10, Section 10.4 Dispersion of White Light by a Glass Prism
---
The textbook explicitly states: "They refract and disperse the incident sunlight, then reflect it internally, and finally refract it again." The key word is internal reflection, not total internal reflection (which rules out option B). Option A uses the general term "reflection," matching the textbook language. Scattering (option C/D) plays no role in rainbow formation. Remember: the three phenomena are refraction + dispersion + (internal) reflection.