The Following Information Relates to Ramesy Manufacturing:
to Produce a Unit

The following information relates to Ramesy Manufacturing:
To produce a unit of product
$$\begin{array} { l l } \text { Cutting Deparment } & 5 \text { mintes per unit } \\\text { Welding Department } & 8 \text { minutes per unit } \\\text { Polishing Department } & 3 \text { minutes per unit } \\\text { Finishing Department } & 4 \text { minutes per unit }\end{array}$$
There is a wait time of 5 minutes before the Cutting Department begins a batch, 15 minutes between the Cutting and Welding departments, a move and pre-wait between Welding and Polishing of 12 minutes, and a move and pre-wait between the Polishing and Finishing departments of 8 minutes.
-Refer to the figure.What is the production rate?

A) 7.5 units per hour
B) 12 units per hour
C) 15 units per hour
D) 20 units per hour