Final answer:
Two investor corporations may not enter jointly into a proprietary business (c).
Step-by-step explanation:
Two investor corporations may not enter jointly into a proprietary (c). This is because a proprietary business is owned and operated by a single individual, not multiple investors or corporations. A sole proprietorship is suitable for individuals seeking to run their own business without the formal structure of a partnership or corporation. In contrast, partnerships involve two or more individuals or entities, and corporations have a complex structure, being owned by shareholders and managed by a board of directors. These business entities allow corporations to undertake a variety of business arrangements outside the limitations of a sole proprietorship.