23) Variable manufacturing overhead is applied to products on the basis of standard direct labor-hours. If the labor efficiency variance is unfavorable, the variable overhead efficiency variance will be: A) zero. B) unfavorable. C) favorable. D) either favorable or unfavorable. 24) Which of the following would produce a labor rate variance? A) Excessive number of hours worked in completing a job. B) Poor quality materials causing breakage and work interruptions. C) Use of persons with high hourly wage rates in tasks that call for low hourly wage rates. D) An unfavorable variable overhead rate variance