Answer:
The correct answer is the letter b. Self interest.
Explanation:
According to Adam Smith “it is not the benevolence of the butcher, the brewer and the baker that we expect our dinner, but the consideration they have for their own interests” ie people starting their own business are acting in their own interest, so Adam Smith's idea that influenced Mark to start a business is self-interest. So Mark hopes to make a profit from his business so that he is primarily interested in his own earnings.