The genesis of modern corporations begins with

It began with Joint stock companies

Explanation:

The Joint Stock companies involves different people coming together and putting down large amounts of money(capital) in running a business. They share in the risks and profits of the business and this merger is usually associated with huge sums of money put down with a high profit enough to be shared between the various shareholders. This is how modern corporation began.

it foreshadows the theme of the paragraph and hints the topic that will be discussed in the paragraph!

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