Marten Company has a cost-benefit policy to investigate any variance that is greater than $1,000 or 10% of budget, whichever is larger. Actual results for the previous month indicate the following: Direct materials Direct labor Budget Actual $100,000 $89,000 50,000 54,000 The company should investigate: a. neither the materials variance nor the labor variance. Ob. the materials variance only. O c. the labor variance only. O d. both the materials variance and the labor variance