[单选题]At database startup， you discover that one of the 

A Start the database in OPEN mode， and create a new index tablespace.

B Start the database in OPEN mode， and drop the lost index tablespace from the database.

CStart the database in MOUNT mode， create a new index tablespace， and drop the lost index tablespace from the database.

D Start the database in MOUNT mode， drop the lost index tablespace from the database， open the database， and create a new index tablespace.