Assuming you are talking about America in general using the statement American.
-Valuing what other cultures offer
-Respect for differences
-Recognition of an abundant diverse amount of cultures
Let us dissect each sentence to tell which of these does not follow the rules for subject-verb agreement.
A.) The subject is 'each of the students' while the verb is 'is'. More particularly, the verb refers to 'each' which is singular. So, this is correct.
B.) The subject is 'student' while the verb is 'were'. The word 'were' is the paste tense of are which is used for a plural subject. But since student is singular, then the verb should have been 'was'. So, this is incorrect.
C.) The subject is 'my dog and my cat' which pertains to two nouns, thus it is plural. It agrees with its plural verb 'are'.
D.) The subject is 'Tom' while the verb is 'does'. Both are intended for singular use. So, this is correct.
Therefore, the answer to this is letter B.
It is A because itis not it;s means it is and that would not make sence
