Which columns should you designate as SPARSE?

HOTSPOT
You use SQL Server 2014. You create a table within a database by using the following DDL:

The following table illustrates a representative sample of data:

The system is expected to handle 50 million orders a month over the next five years.
You have been instructed by your Team Lead to follow best practices for storage and
performance in the utilization of SPARSE columns.
Which columns should you designate as SPARSE? To answer, mark each column as
SPARSE or NOT SPARSE in the answer area.

Answer:

Explanation:

Note:
Sparse columns are ordinary columns that have an optimized storage for null values. Sparse
columns reduce the space requirements for null values at the cost of more overhead to
retrieve nonnull values. Consider using sparse columns when the space saved is at least 20
percent to 40 percent.