A tractor operated 9-row precision planter has 16 cells on the metering plates. The speed ratio of the metering plates to the ground drive wheel is 1: 2 and the rolling diameter of the ground drive wheel is $40 \mathrm{~cm}$. Assuming no skid, the plant to plant spacing in rows in $\mathrm{mm}$ is
(A) 39
(B) 50
(C) 157
(D) 314
A tractor operated 9-row precision planter has 16 cells on the metering plates. The speed ratio of the metering plates to the ground drive wheel is 1: 2 and the rolling diameter of the ground drive wheel is $40 \mathrm{~cm}$. Assuming no skid, the plant to plant spacing in rows in $\mathrm{mm}$ is
(A) 39
(B) 50
(C) 157
(D) 314