Option A: The prefix 'in' forms a word with 'visible': invisible.
'Invisible' means 'not visible', 'not seen by the eyes'.
It forms a complete meaningful sentence: internal lives cannot be seen by the eye.
Hence, option A is correct.
Options B, C and D: The prefixes 'dis', 'im' and 'il' do not form a new word with 'visible'.
The words 'disvisible', 'imvisible' and 'ilvisible' do not exist in standard English language. Hence options B, C and D are wrong.