Explanation:

- Let's break down the code:

- 'for the victory sign' = 'si vi th fo'

- 'empty the apartment now' = 'no ap th em'

- 'now for the finale' = 'fi th fo no'

- 'for empty sign victory' = 'vi si em fo'

- From the above, we identify:

- 'for' = 'fo'

- 'the' = 'th'

- 'victory' = 'vi'

- 'sign' = 'si'

- 'empty' = 'em'

- 'now' = 'no'

- 'apartment' = 'ap'

- 'finale' = 'fi'

- Analyzing the phrase 'the empty sign':

- 'the' = 'th'

- 'empty' = 'em'

- 'sign' = 'si'

- So, 'the empty sign' is coded as: 'si em th'

Option 3: si em th is the correct answer.