An exothermic reaction releases heat. An endothermic reaction absorbs heat. Burning gas releases heat so it would be exothermic. Acid and water react heating the beaker would be exothermic because it releases heat from the reaction. Hope this helps! ;)
(1) 25 ml of water at 95 degrees Celsius is your answer. Temperature is the average kinetic energy of the substance that it measures, therefore the highest temperature choice, aka #1, is your answer.