Each function below describes how something changes. Use the description to determine which function(s) describe a linear relationship. f(t): The intensity of light is proportional to the distance from the source. g(t): The volume of water in a tank decreases by two cubic inches per hour. h(t): The temperature increases by a factor of two. m(t): The cost decreases at a rate of five percent. O g(t) only O h(t) and m(t) only O f(t) and g(t) only O f (t ) only O g(t) and h(t) only