In ultrasound technology, which type of sound wave-object interaction creates echoes that are processed to form images?

diffraction
reflection
refraction

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 big glowy thing is called the sun it is a star in our galaxy and is over 1 million degrees