CEO or Managing Director? Who will i be?

Ok, i would say i am still a freelancer. One of my client who is CEO of his company, an Omani wanted me to start a business and he is ready to sponsor me. He would provide me with the Visa. He gave me three options like
1. Work as an employee
2. Partnership Business
3. Sole Proprietorship

Well since am just an engg student i would like to know what sole proprietorship means. I dont know is it something that i assume right now. If i select the Sole Proprietorship option, what would be my designation? Is it a CEO or Managing Director? I know i will be the owner of the business but which one would be correct to say CEO / Managing Director ?

THANKS IN ADVANCE!