A b c or d please help me

If i can still dissolve more sugar into the solution at a certain temperature what would i call that solution

Which organism develops breathing organism develops breathing organs from pharyngeal arches? shark, spider, sea star, sea horse

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?