which cannot contain NULL?

View the Exhibit and examine the data in the PRODUCTS table.
Which statement would add a column called PRICE, which cannot contain NULL?

A.
ALTER TABLE products
ADD price NUMBER(8,2) NOT NULL;

B.
ALTER TABLE products
ADD price NUMBER(8,2) DEFAULT NOT NULL;

C.
ALTER TABLE products
ADD price NUMBER(8,2) DEFAULT 0 NOT NULL;

D.
ALTER TABLE products
ADD price NUMBER(8,2) DEFAULT CONSTRAINT p_nn NOT NULL;