Case 3-2 Judy Has Begun to Apply the Basic Information That You

Multiple Choice

Case 3-2
Judy has begun to apply the basic information that you have given her about schemas, and she would now like your help in mastering the details of how schemas work. 
Judy has included the following element definition in her schema:
     <xs:element name="ingredient">
            <xs:complexType>
                  <xs:sequence>
                        <xs:element name="name" type="xs:string" />
                        <xs:element name="amount" type="xs:string" />
                  </xs:sequence>
            </xs:complexType>
     </xs:element>
-Judy would like to indicate that the "substitution" attribute is a required attribute. Which of the following attribute definitions shows how to accomplish this?

A) <xs:attribute name="substitution" type="xs:string" use="required" />
B) <xs:attribute name="substitution" type="xs:string" required="yes" />
C) <xs:attribute name="substitution" type="xs:string" use="mandatory" />
D) <xs:attribute name="substitution" type="xs:string" status="mandatory" />