Consider the following code:

```python
try:
numerator = 10
denominator = 0
result = numerator / denominator
print(result)
except ZeroDivisionError:
print("Error: Denominator cannot be 0.")
```

Which of the following is the correct expected output?

A. ZeroDivisionError
B. Error: Denominator cannot be 0
C. 10/0
D. NaN

In this question, the code provided includes a try-except block in programming, specifically in Python. The purpose of this block is to handle exceptions, which are errors that occur during the execution of a program.

The code attempts to divide a numerator, which is 10, by a denominator, which is 0. In mathematics, division by zero is undefined and not allowed. In programming, particularly in Python, this results in a ZeroDivisionError.

Here's a breakdown of the code execution:

The try block is entered, and the code attempts to compute result = numerator / denominator, which is 10 / 0.
Because the denominator is zero, Python raises a ZeroDivisionError.
The except ZeroDivisionError block catches this specific error.
Inside the except block, the message "Error: Denominator cannot be 0." is printed to inform the user that the error occurred due to an attempt to divide by zero.

Hence, the correct expected output of the code is B) "Error: Denominator cannot be 0.". This message clearly communicates to the user why the division operation failed.