To check the code coverage of a class after running all tests, the developer should view the code coverage percentage for the class using the Overall Code Coverage panel in the Developer Console Tests tab. This panel shows the code coverage for each class and trigger in the org, as well as the overall code coverage percentage.
The developer can also double-click on a class or trigger name to see the code coverage details, such as which lines are covered or not covered by tests.
The other options are not correct because:
* A. View the Code Coverage column in the list view on the Apex Classes page. This option only shows the code coverage percentage for each class, but not the details of which lines are covered or not covered by tests. It also does not show the code coverage for triggers or the overall code coverage percentage.
* B. View the Class Test Percentage tab on the Apex Class fist view m Salesforce Setup. This option does not exist in Salesforce Setup. There is no such tab or view for Apex classes.
* D. Select and run the class on the Apex Test Execution page in the Developer Console. This option only runs the test methods in the selected class, but does not show the code coverage for the class or other classes and triggers in the org.
References:
* : Testing and Code Coverage
* : Developer Console

Creating test classes ensures that the Apex class works according to specifications by validating the functionality under various scenarios and edge cases. Running tests in the Developer Console provides detailed feedback on whether the class meets requirements.
Reference:Testing Apex
Incorrect Options:
A:Savepoints and rollbacks are used to manage transactions, not for validation.
B:Try/catch blocks handle exceptions but do not ensure the code adheres to specifications.
C:Execute Anonymous only tests small portions of code interactively, not comprehensive functionality.
Below is the formatted response for the provided question, adhering to the specified format and requirements.
The question falls under the Salesforce Platform and Declarative Features topic, as it involves Visualforce page components and their security implications, which is a key focus of the Salesforce Platform Developer I certification. The answer is based on official Salesforce Platform Developer I documentation, with a comprehensive explanation and references to relevant Salesforce documentation.