The weekly quantity demanded of premium virtual reality headsets (Brand X) falls from 12,000 12,000\,12,000 to 9,000 9,000\,9,000 units when the price of a compatible motion-tracking sensor (Brand Y) increases by 20%.
In relation to the price of Brand Y sensors, what is the cross elasticity of demand for Brand X headsets?
+1.25+1.25+1.25
−1.25-1.25−1.25
−0.80-0.80−0.80
+0.80+0.80+0.80