Once a company acquires 5% of the outstanding shares of a publicly held company, it must:
a. Promise not to try to buy out the company in which it has made an investment (purchased 5% or more of the outstanding shares).
b. File a 13d with the Securities and Exchange Commission, stating whether it intends to eventually make an offer to buy out the company or be a passive investor.
c. Attempt to buy all the remaining shares outstanding within twelve months.
d. Try to gain control by launching a proxy contest.