Calculate a Level $3$ "efficiency" variance for materials given the following information:

budgeted units produced: $500$

budgeted material used in kgs: $700$

budgeted total material cost: $$9100$

actual units produced: $700$

actual kgs used: $1050$

actual total material cost: $$10500$

$$880$U

$$910$U

$$910$F

none of the listed answers are correct

$$880$F