Assertion A : If A, B, C, D are four points on a semi-circular arc with centre at 'O' such that

Assertion A : If A, B, C, D are four points on a semi-circular arc with centre at 'O' such that

$\overrightarrow{\mathrm{AB}}+\overrightarrow{\mathrm{AC}}+\overrightarrow{\mathrm{AD}}=4 \overrightarrow{\mathrm{AO}}+\overrightarrow{\mathrm{OB}}+\overrightarrow{\mathrm{OC}}$

Reason R : Polygon law of vector addition yields

$\overrightarrow{\mathrm{AB}}+\overrightarrow{\mathrm{BC}}+\overrightarrow{\mathrm{CD}}+\overrightarrow{\mathrm{AD}}=2 \overrightarrow{\mathrm{AO}}$

In the light of the above statements, choose the most appropriate answer from the options given below :