What does the method dictionary.update({"key": "value"}) do?

The method dictionary.update({"key": "value"}) combines the functionality of adding a new key-value pair and replacing the value for an existing key within a dictionary. When this method is called:

• If the specified key ("key" in this case) does not exist in the dictionary, it adds this new entry to the dictionary.

• If the specified key already exists, the method updates the value associated with that key to the new provided value ("value").

This dual functionality makes the method quite versatile for managing dictionaries, as it ensures that any desired key-value pair is correctly represented in the dictionary, whether it’s an addition or an update.

The other options do not fully encompass the capabilities of the update method, as they focus solely on one aspect—either addition or replacement—but the correct understanding is that both actions can occur depending on the current state of the dictionary. Thus, C accurately captures the complete behavior of the update method.