Concept:Euclid is known as the father of geometry because his work “Elements” systematically organized and proved many geometric principles, forming the foundation of classical geometry.Explanation:Around 300 BC, Euclid compiled and formalized existing geometric knowledge into a single, logical framework in his book “Elements.” This text introduced axioms, theorems, and rigorous proofs that became the standard reference for geometry for centuries. While other mathematicians like Pythagoras and Bhaskaracharya also contributed, Euclid’s comprehensive and enduring impact earned him this title.Answer:Option D – Euclid