Day trip from Copenhagen

Hi! I am visiting Copenhagen and I’ve been here for 3 days already . I have an extra day and I’m trying to decide what to do. I have 3 options, and other suggestions are welcome. 1) going to Amager beach and Dragør; 2) going to Malmo; 3) going to Møns Klint (but I feel it will be an expensive trip). What do you recommend? Thanks for your help!