Which of the following reactions below could be properly categorized as a synthesis reaction?

A synthesis reaction is a type of reaction in which multiple reactants combine to form a single product. Synthesis reactions release energy in the form of heat and light, so they are exothermic. An example of a synthesis reaction is the formation of water from hydrogen and oxygen.

the answers would be

the first one and the second one

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.