Some legal obligations

I am somewhat confused with the practice question no. 5 for the chapter "some legal obligations" Question: Which two of the following are correct with respect to uk data protection act provisions? Options: 1) The act applies to personal data processed wholly or partially automatically. 2) The act applies to non-personal data held on a computer. 3) The act applies to all data held on a computer. 4) The act applies to personal data held manually 5) There are some restrictions on your to see your personal data. Now, the fourth option may have been incorrect if the word "only" was included after the word manually, but since the word "only" is not included it seems to be correct. So why is the fourth option not correct? Also, it would be useful to understand the reason for option 3 being incorrect.