When Inserting a Row into a Table,how Can You Indicate

Multiple Choice

When inserting a row into a table,how can you indicate that a row contains a NULL value?​

A) ​In the VALUES clause,substitute two single quotation marks for the NULL value.
B) ​In the VALUES clause,include the keyword NULL in the position where the value should be listed.
C) ​In the VALUES clause,include a blank space in the position where the value should be listed.
D) ​both a and b