How can I solve for B, C, and D in Labor Efficiency Variance?

Labor rate variance = 4,800 hours [(8.57) - $8.50] = $350 favorable

Labor efficiency variance = (b) [(c) - 5,000 hours] = $(d)

On the appropriately labeled line, identify each missing item by name (a through c) and show the missing value (a through d). Show supporting computations in the space provided.

B=Standard Hourly Rate= $_______________

C=Standard hours=______________ hours

D=$______________