Explanation:

The correct answer to the question is option 'B' - Are. Let's break down the explanation into headings and bullet points for clarity.

Subject-Verb Agreement:
- In English grammar, subject-verb agreement is the agreement between the subject and the verb in a sentence.
- The subject is the person or thing that performs the action or about which something is stated.
- The verb is the action word or words that express what is being done or what happens.

Singular and Plural Forms:
- The verb form changes depending on whether the subject is singular or plural.
- Singular subjects take singular verb forms, while plural subjects take plural verb forms.

Dictionary and Atlas:
- In the given sentence, the subject is "a dictionary and an atlas."
- "A dictionary and an atlas" refers to two items, but it is considered as a single subject because both items are connected by the conjunction "and."
- Since the subject is singular, the verb form should be singular as well.

Verb Forms:
- The verb "is" is the singular form of the verb "to be."
- The verb "are" is the plural form of the verb "to be."

Applying Subject-Verb Agreement:
- In the given sentence, the subject "a dictionary and an atlas" is singular.
- Therefore, the correct verb form to use is the singular form "is."

Conclusion:
- Based on the rules of subject-verb agreement, the correct answer to the question is option 'B' - Are.
- However, this answer is incorrect as it does not follow the rules of subject-verb agreement.
- The correct answer should be option 'A' - Is, as the subject "a dictionary and an atlas" is singular and requires a singular verb form.