In the Fifteenth Century, Did the West Know That India

In the fifteenth century, did the West know that India already had Christians?

A) Yes, Catholics and Protestants alike called them Thomas Christians
B) Yes, through the Silk Road, Rome had been supporting missions to India since the ninth century
C) No, explorers were surprised to find them
D) No, it wouldn't be until the seventeenth century that Christianity would take hold in India