(ii) CSR adds cost to organisational activities and reduces profit levels
x
(iii) Social responsibility may have commercial benefits
x
(iv) Social responsibility is a concern confined to business organisations
x
Rationale: Statement (i) is incorrect, because there is no such 'guarantee'; statement (ii) because it is not necessarily so, and statement (iv) because other organisations (eg charities, government bodies) are often more concerned with social responsibility than businesses.
Ways in: It is always worth checking to see if logic helps. Words like 'guarantee' often signal an untrue statement, because they make such extreme claims. And if statement (i) is therefore incorrect, you've halved your options. It should then be obvious that (iv) is incorrect (if you think about a hospital, say).