Use the diagram to answer the question.

A parallel circuit diagram with a voltage source of 12 volts and a total current of 4 amps coming from the power source. the current is split through two resistors. Resistor 2 receives 2 amps of current and resistor 1 receives an unknown current.

What is the ratio of resistances R1:R2?

1:2

2:1

1:1

1:3