"The people who own shares in the corporation" has the most control over a corporation.
Option: A
Explanation:
At least in theory a company is owned and operated by its members. In a joint-stock company the participants are known as shareholders and each of their interests in the company's ownership, control, and income is calculated by the shareholding portion of the company they own.
The ultimate owners of a company are shareholders or stockholders. They are eligible to elect directors, decide on major corporate activities (including mergers) and participate in the corporate profits.