Q36 : Why the answer is B ?

These questions refer to the following graph, which is In what month was gas use in one of drawn to scale. the years nearly double that for the same month in the other year? A HOUSEHOLD'S MONTHLY GAS USE FOR 1987 AND 1988 150 150 February 1987 (Total use: 687 CCF) 140+ - - -1988 (Total use : 706 CCF) -140 July 00000 August 130 + 130 September 120+ 120 October 110+ -110 100 +100 90- +90 Gas Use in CCF (1CCF = 100 cubic feet) 80 -80 Gas Use in CCF -70 60 50 40 -30 20+ 10+ 36 Jan. Mar.- July- Oct. Feb. Apr. May Nov. Dec. June- Aug. Sept. @B