On 10/24/14, Alan Eustace, a Google Executive, jumped from an altitude of nearly 136,000 feet (25.8 mi.) above the Earth, breaking the record set by Felix Baumgartner in 2012. Ignoring air resistance, how long did it take him to reach the speed of sound (340 m/s)?

The answer is  a.first and third quarters 

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

Answer mechanical energy;