The answer is B.
A cannot be the answer is melting is a physical change. No chemical reaction took place.
B is the answer as it is a EXOTHERMIC REACTION so heat will be given off.
C cannot be the answer as dissolving is basically atoms becoming ions, not a chemical reaction whereby a reactant reacts with another reactant to form a product.
D cannot be the answer. Same reason as for why A is not the answer.
Cheers.
Laurentia, also called the North American Craton, is a huge continental craton. It<span> forms the ancient </span>geological<span> core of the </span>continent of North America.<span> It is made up of present day North America and Greenland. About 300 million years ago, it collided with the southern hemispheric continent of </span>Gondwana<span> and formed the supercontinent called Pangaea.</span><span> </span>
