Solution:A. Grassroot movements entail participatory democracy: Correct. Grassroot movements involve direct participation of local communities in decision-making, ensuring bottom-up democratic processes.
D. Grassroot movements can empower marginalised sections: Correct. These movements often focus on Dalits, tribal groups, women, farmers, and labourers, enabling representation and empowerment.
B. Incorrect: Political mobilisation is not a necessary condition; many grassroots movements are community-driven without formal political mobilisation.
C. Incorrect: Environmental movements such as Chipko Movement, Narmada Bachao Andolan, Silent Valley Movement are classic examples of grassroots environmental struggles.
Thus, correct combination: A and D only