Which of the Following Is the Correct Statement of the Marginal

Multiple Choice

Which of the following is the correct statement of the marginal rule for optimal input proportions? The input proportion is optimal when

A) $\mathrm{P}_{\mathrm{A}}$ = $\mathrm{P}_{\mathrm{B}}$ .
B) MP $\mathrm{P}_{\mathrm{A}}$ = MP $\mathrm{P}_{\mathrm{A}}$ /MP $\mathrm{P}_{\mathrm{B}}$ . .
C) $\mathrm{P}_{\mathrm{A}}$ × MP $\mathrm{P}_{\mathrm{A}}$ = $\mathrm{P}_{\mathrm{A}}$ /MP $\mathrm{P}_{\mathrm{B}}$ . × MP $\mathrm{P}_{\mathrm{A}}$ /MP $\mathrm{P}_{\mathrm{B}}$ . .
D) $\mathrm{P}_{\mathrm{A}}$ / $\mathrm{P}_{\mathrm{A}}$ /MP $\mathrm{P}_{\mathrm{B}}$ .= MP $\mathrm{P}_{\mathrm{A}}$ /MP $\mathrm{P}_{\mathrm{B}}$ .