In 550 bc, which leader began the persian empire along the northeast coast of the persian gulf?

Cyrus the Great.

Explanation:

The Persian Empire rose as a combination of semi-nomadic tribes who reared goats, sheep and cattle on the Iranian plateau. Cyrus the Great, was a leader of one such tribe who began defeating the nearby kingdoms including Lydia, Media and Babylon. By establishing the Achaemenid Empire, the first Persian Empire, he brought together all these kingdoms together. His empire was a hub of religion, culture, art,  science and technology for more than two centuries.

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.