Concept:The prize-winning app was built by Noida schoolgirls for a global tech competition.Explanation:The app is named MAITRI.It won the bronze medal at the Technovation Challenge in San Francisco, United States.This challenge is the world’s largest technology and entrepreneurship programme for girls.MAITRI helps old-age homes and orphanages register and organise meetings.This allows children and senior citizens to spend time together.Thus, MAITRI is the correct app associated with Noida schoolgirls and the US tech prize.Answer:Option D. MAITRI.