Que cantidad de calor se necesita para evaporar 15g de agua a 100 C

Definitely the indoraptor

I'm not sure what your asking buddy.. but i know that you can weld two peices of steel by pure force and pressure.

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current