In the following question, a part of the sentence (a word or phrase) has been highlighted in bold. Four different ways of writing the word or phrase have been given in the options (1), (2), (3), and (4). Find the correct replacement of the given bold word or phrase. If the given word or phrase is grammatically correct, then select option (5).

The city was battered by heavy rain and which caused flash floods and landslides killing at least ten people.