If a clustered index is dropped by using MOVE TO, any nonclustered indexes on the base table are rebuilt, but they remain in their original filegroups or partition schemes. If the base table is moved to a different filegroup or partition scheme, the nonclustered indexes are not moved to coincide with the new location of the base table (heap). Therefore, even if the nonclustered indexes were previously aligned with the clustered index, they might no longer be aligned with the heap.
which would appear to contradict the given answer.
What am I missing here?
non-clustered indexes also contain the clustered index column(s) to identify the location of the actual rows to retrieve data from. If the clustered index is dropped then the non-clustered indexes have to be rebuilt to remove the clustered index and replace it with row ID information
I thought exactly the same and got it right. Very good question Jagadish.