What is a golden grand slam in tennis?

a) Wining 3 major championships in a calendar year

b) Wining 2 major championships in a calendar year

c) Wining 4 major championships in a calendar year

d) none of these

In tennis golden grand slam is term used when an individual player wins all four major championships in a calendar year. The four major championships are Australian, Wimbledon, US Open and French Open.