Answer B is correct. The presence of a condition should not affect the addition of an index to the view. You must ensure that the WITH SCHEMABINDING option is performed when creating the view if you are going to be applying indexes. Because this preparatory step had not been completed, it needs to be done. WITH CHECK applies only to data modified through the view and ensures that when a row is modified through a view, the data remains visible through the view after the modification is committed. DROP EXISTING does not apply because there was no previously created index. Clustered or nonclustered applies to the physical properties of the index and is irrelevant in this case.
For more information, see the following sources: