I’m not too sure… Zoom in so the image is clearer.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a