Assertion A: If A, B, C, D are four points on a semi-circular arc with centre at 'O' such that | AB |=| BC |=| CD |, then A B + A C + A D =4 A O + O…

Assertion A: If A, B, C, D are four points on a semi-circular arc with centre at 'O' such that $\displaystyle |\overrightarrow{\mathrm{AB}}|=|\overrightarrow{\mathrm{BC}}|=|\overrightarrow{\mathrm{CD}}|$, then $$\overrightarrow{A B}+\overrightarrow{A C}+\overrightarrow{A D}=4 \overrightarrow{A O}+\overrightarrow{O B}+\overrightarrow{O C} $$ 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: