Why did britain and russia become involved in a great game

What would lead a historian to consider two events to have a relationship of correlation rather than causation?

Which of the following encouraged westward expansion? a.the government decreased the price of federal land. b.each of these represents actions taken to encourage westward expansion. c.the government decreased the price of federal land d.the second national bank lowered the cost of borrowing money (reduced interest rates)

Jane determines x = 4 and y = 1 is the solution to the following system of equations.