A CNBC new story published 14 December 2021 reports, "OPEC and non-OPEC oil producers, an influential group known as OPEC+, decided on Thursday to stick to a previously agreed upon plan of hiking output by 400,000 barrels per day in January 2022.

However the alliance said in a statement that "the meeting remains in session," meaning they can "make immediate adjustments" should the current market conditions shift.

In what was a hotly anticipated meeting, the energy alliance convened via videoconference to determine whether to stick with its plan to release more oil into the market or to restrain supply amidfears over the omicron Covid-19 variant. Other issues on the table included aU.S.-led release of strategic reservesfrom crude-importing nations andIran's possible re-entry into oil markets."

a Identify the market structure where OPEC operates.

b Discuss extensively 2 features of that market structure