Answer:
B, C
Explanation:
To ensure that Pricing_Structure__c records are available when the test class is executed, the developer can use either a Test Data Factory class or the @isTest(seeAllData=true) annotation. A Test Data Factory class is a reusable class that creates test data for multiple test classes. The developer can use this class to insert the Pricing_Structure__c records before running the test methods. The @isTest(seeAllData=true) annotation allows the test class to access all data in the organization, including the Pricing_Structure__c records. However, this annotation should be used sparingly and only when strictly necessary, as it may cause the test to fail due to data changes or dependencies. The Test.startTest() and Test.stopTest() methods are used to mark the start and end of the test execution, and do not affect the data availability. The without sharing keyword on the class declaration does not affect the test data isolation, and only determines whether the class enforces the sharing rules of the current user or not. References:

Isolation of Test Data from Organization Data in Unit Tests (Salesforce Developer Documentation)
Creating Test Data for Apex Tests (Salesforce Developer Documentation)
Using the isTest Annotation (Salesforce Developer Documentation)
Using the startTest and stopTest Methods (Salesforce Developer Documentation)
Using the with sharing or without sharing Keywords (Salesforce Developer Documentation)
Free Salesforce Platform Developer 1 Practice Exam (With Answers)Â (Salesforce Ben)...