The sentence from the article that BEST supports the statement is:
Russia is a major producer of oil and natural gas, adding to concern and uncertainty across the world. (Option A)
It is to be noted that Russia is one of the major producers of oil in the world. Hence, it wields considerable influence on the prices of oil both in Ukraine and other parts of the world.
From the information provided since there is instability in the region, it is likely to affect oil prices. This is is why option A is the correct answer.
Learn more about Russia at:
https://brainly.com/question/510861