The thickness “t” of a single flat lacing should not be less than

A

$$\frac{1}{30^{th}}$$ length between inner end rivets

B

$$\frac{1}{40^{th}}$$ length between inner end rivets

C

$$\frac{1}{50^{th}}$$ length between inner end rivets

D

$$\frac{1}{60^{th}}$$ length between inner end rivets