Final answer:
Glasswing International is the NGO in El Salvador that primarily focuses on providing educational support to Salvadoran families. It collaborates with various parties to create sustainable community-based programs that significantly impact education, health, and societal improvement.
Step-by-step explanation:
The non-governmental institution in El Salvador that primarily focuses on providing educational support and resources to Salvadoran families is d) Glasswing International. Glasswing International is an organization that works with communities in Central America to address issues of education, health, and violence through community empowerment, education, and healthcare initiatives. This organization collaborates with volunteers, government agencies, private companies and other NGOs to create programs that have a sustainable impact on Salvadoran society.
NGOs play a critical role in helping improve the standard of living in many countries by focusing on critical areas such as education, health, and infrastructure. Support from various agencies, including foreign aid programs like the Alliance for Progress and independent groups like Red Cross and CARE, has been essential in setting up schools and other vital structures in low- and middle-income countries.