The correction to be applied to each 30 m chain for a line measurement along a slope of 0 is

A

$$ 30 ( 1 - \cos \theta ) $$

B

$$ 30 ( 1 - \sin \theta ) $$

C

$$ 30 ( 1 - \tan \theta ) $$

D

$$ 30 ( 1 - \cot \theta ) $$