Case 2-2 Rosalind Wants to Add Attribute Declarations to Her DTD, and DTD

Multiple Choice

Case 2-2
Rosalind wants to add attribute declarations to her DTD, and she turns to you for information about the possible attribute types.
-You help Rosalind write the declaration of the "semester" attribute described in the previous problem. Which of the following is an appropriate declaration for this attribute?

A) <!ATTLIST course semester (fall | spring | summer) #REQUIRED>
B) <!ATTLIST course semester (fall, spring, summer) #REQUIRED>
C) <!ATTLIST semester course (fall | spring | summer) #REQUIRED>
D) <!ATTLIST semester course (fall, spring, summer) #REQUIRED>