First, let's find the amount of flour she used. (So it makes more sense)
4/8= 1/2
3*1/2= 1.5
Janet uses 1 and 1/2 cups of flour this week.
That is less than four cups, so we can eliminate statement A and B.
It is not less than one though because 1.5>1
"C" is the correct answer. She uses less than four cups because 3/8 (1.5) is less than 4.
I hope this helps!
~kaikers