What is the width of badminton court for a single player?

What is the width of badminton court for a single player?

A. 5.18 meter 
B. 6.10 meter
C. 0.40 meters
D. 5.20 meter

The full width of the court is 6.1 metres (20 ft), and in singles this width is reduced to 5.18 metres (17 ft). The full length of the court is 13.4 metres (44 ft).