B C and E are correct
https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_exception_custom.htm

B, C and E are correct options.

The correct answers are:

**B. A custom exception class name must end with "Exception".**
**C. A custom exception class must extend the system Exception class.**
**E. A custom exception class can implement one or many interfaces.**

Here's a breakdown of why these are the correct answers:

* **Option B:** This is a convention to clearly indicate that the class is an exception class.
* **Option C:** This is a requirement in Apex. All custom exception classes must extend the `Exception` class to inherit its behavior and properties.
* **Option E:** Custom exception classes can implement interfaces to add additional functionality or behavior. For example, you could implement the `Serializable` interface to allow the exception to be serialized and deserialized.

The other options are incorrect:

* **Option A:** Custom exception classes can contain member variables and methods. These can be used to store additional information about the exception or provide custom behavior.
* **Option D:** Custom exception classes cannot extend other classes besides the `Exception` class. They must directly extend the `Exception` class....

B, C and E are correct