The correct answer is: Panaji.
Panaji is the capital of the Indian state of Goa. It is located on the banks of the Mandovi River, in the northern part of the state. Panaji is a popular tourist destination, known for its beaches, churches, and Portuguese colonial architecture.
Quela is a town in the Indian state of Goa. It is located in the South Goa district, on the banks of the Zuari River. Quela is a popular tourist destination, known for its beaches, temples, and Portuguese colonial architecture.
Saligao is a town in the Indian state of Goa. It is located in the North Goa district, on the banks of the Chapora River. Saligao is a popular tourist destination, known for its beaches, churches, and Portuguese colonial architecture.
Vasco da Gama is a town in the Indian state of Goa. It is located in the South Goa district, on the banks of the Zuari River. Vasco da Gama is a major port city, and is also a popular tourist destination, known for its beaches, churches, and Portuguese colonial architecture.
None of these options is the biggest city in Goa. The biggest city in Goa is Panaji.