A. Vissu said that they passed by a beautiful lake when they had gone on a trip to Goa.
B. Vissu said that they has passed by a beautiful lake when they went on a trip to Goa.
C. Vissu said that they had passed by a beautiful lake when they had gone on a trip to Goa.
D. Vissu said they passed by a beautiful lake when they went on a trip to Goa.
✅ The correct answer is option C.