The correct answer is option 'A': the finally part of a try-except-finally block is always executed.

Explanation:

A try-except-finally block is a construct in programming languages that allows you to handle exceptions or errors that may occur during the execution of a program. The syntax for a try-except-finally block is as follows:

```
try:
# Code that may raise an exception
except ExceptionType:
# Code to handle the exception
finally:
# Code that will always be executed
```

The finally block is used to perform any necessary cleanup or finalization tasks, regardless of whether an exception occurs or not. It is executed regardless of whether an exception is raised and caught or not.

Key Points:
- The finally block is always executed, regardless of whether an exception occurs or not.
- It is typically used to release resources, such as closing files or database connections, that were acquired in the try block.
- The finally block is useful when you want to ensure that certain code is executed no matter what happens in the try block.
- If an exception occurs and is not caught by any except block, the finally block will still be executed before the exception propagates up the call stack.
- If an exception is caught by an except block, the finally block will be executed after the except block is executed.

Example:

```python
try:
# Code that may raise an exception
print("Inside try block")
raise ValueError("An error occurred")
except ValueError:
# Code to handle the exception
print("Inside except block")
finally:
# Code that will always be executed
print("Inside finally block")
```

Output:
```
Inside try block
Inside except block
Inside finally block
```

In the above example, even though an exception is raised and caught by the except block, the finally block is still executed. This ensures that any necessary cleanup tasks are performed before the program continues execution.