Explanation:

As per given information coding description is as follows:

'business is easy to do' - 'pa ro se yo ze'……1)

'business aries difficulty in life' - 'lo fe pa so te'. ……2)

'life is easy' - 'so ro yo'. ……3)

'difficulty to do work' - 'se lo ze me' ……

4) 'easy business life' - 'pa yo so'. ……

5) From 1) and 2) business is coded as: pa

From 1), 2) and 5) easy is coded as: yo

From 1), 2) and 5) life is coded as: so

From 1) and 3) ‘is’ is coded as: ro

From 2) and 4) ‘difficulty’ is coded as: lo

From 1), 2), 3) and 4) ‘to’ is coded as: Either ‘se’ or ‘ze’

From 1), 2), 3) and 4) ‘do’ is coded as: Either ‘se’ or ‘ze’

From 1), 2), 3) and 4) ‘work’ is coded as: me

From 1), 2), 3) and 4) ‘aries’ is coded as: Either ‘fe’ or ‘te’

From 1), 2), 3) and 4) ‘in’ is coded as: Either ‘fe’ or ‘te’

'life is complicated' can written as ‘so fa ro’ complicated is the new word for coding so we should write new code also which is fa. So answer is 4).