In 2018, the Price of Oil Increased, Which in Turn

In 2018, the price of oil increased, which in turn contributed to a rise in the price of natural gas. This can best be explained by saying that oil and natural gas are

A) complementary goods, and the higher price for oil increased the demand for natural gas.
B) substitute goods, and the higher price for oil increased the demand for natural gas.
C) complementary goods, and the higher price for oil decreased the supply of natural gas.
D) substitute goods, and the higher price for oil decreased the supply of natural gas.