Two cars have a ‘rear end' collision. A 1200 kg Honda moving at 20.0 m/s strikes a 1000.0 kg Ford moving at 15 m/s. Their bumpers become locked and they continue to
move as one mass. What is their final velocity?

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

The fertilized egg  begins to develop into a hollow ball of cells called the blastocyst. 

Wouldnt it be millileter