Hi tutors, I don't quite know what is the meaning of "utilizing the maximum available margin of 10%". What is the difference between this and just "buy shares on the margin of 10%"? And I am not clear about the third and fourth options.

d. An investor buys shares in a public company for $35.00 per share, utilizing the maximum available margin of 10%. Assuming the shares increase in value. this investor's return on investment before interest and commission will be: (1 mark) (9 The same as the return on investment earned by an investor who did not buy on margin 0 Double the return on Investment earned by an Investor who did not buy on margin 0 Cannot be determined V None of the above