You work as the IT professional in an international company which is named wiikigo. You are experienced in implementing and administering a network operating system. You are specialized in configuring IP addressing and services. Configuring name resolution and network access and so on.Your company is desigiing its network. The network will use an IPv6 prefix of 2001:DB8: BBCC:0000::/53. You have to identify an IPv6 addressing scheme that will support 2000 subnets. Which network mask should you use?（）

A. You should use /63.
B. You should use /64.
C. You should use /61.
D. You should use /62.