Social exclusion is a process through which certain individuals or groups are marginalized or excluded from the various aspects of society, including facilities, benefits, and opportunities. It is a form of discrimination that can occur on the basis of various factors such as race, gender, ethnicity, socio-economic status, disability, or age. In this context, the correct answer is option 'D', which includes all of the above-mentioned factors.

Facilities:
- Social exclusion denies individuals access to basic facilities necessary for their well-being and development. This can include essential services such as healthcare, education, housing, transportation, and sanitation. When certain individuals are excluded from accessing these facilities, it hinders their ability to lead a dignified and fulfilling life.

Benefits:
- Social exclusion also deprives individuals of various social and economic benefits. These benefits can include social security, welfare programs, financial assistance, employment opportunities, and legal protections. When individuals are excluded from these benefits, they may face increased vulnerability, poverty, and a lack of social support.

Opportunities:
- Social exclusion limits the opportunities available to individuals to participate fully in society. This can manifest in various ways, such as limited access to employment, education, political participation, cultural activities, and social networks. When individuals are denied these opportunities, it perpetuates inequality and hampers their ability to contribute to society and achieve their full potential.

Importance of addressing social exclusion:
- Social exclusion has profound negative consequences for individuals and society as a whole. It reinforces inequality, perpetuates poverty, and hinders social cohesion. By denying certain individuals access to facilities, benefits, and opportunities, society misses out on their potential contributions and talent. Moreover, social exclusion undermines the principles of equality, human rights, and social justice.

Conclusion:
- Social exclusion denies individuals access to facilities, benefits, and opportunities, ultimately leading to marginalization and inequality. It is important for societies to address social exclusion by promoting inclusivity, equal opportunities, and social justice for all. This can be achieved through policies and practices that aim to remove barriers, challenge discrimination, and create a more inclusive and equitable society.