The formula for current in a resistor is
Current = (voltage) / (resistance)
You'll notice that Resistance is in the denominator of the fraction,
and that means that the current changes in the opposite direction
from the resistance. Smaller resistance means bigger current, and
bigger resistance means smaller current.
The resistors in your question are connected in parallel, so they
all have the same voltage across them. According to the simple
formula for current, then, the smallest resistor will have the biggest
current through it. That would be the 4-ohmer.