Assertion A : If A, B, C and D are four points on a semi-circular arc with centre at 'O' such that \( |\overrightarrow {AB}| = |\overrightarrow {BC}| = |\overrightarrow {CD}| \), then \( \overrightarrow{AB} + \overrightarrow{AC} + \overrightarrow{AD} = 4\overrightarrow{AO} + \overrightarrow{OB} + \overrightarrow{OC} \).
Reason R : Polygon law of vector addition yields \( \overrightarrow{AB} + \overrightarrow{BC} + \overrightarrow{CD} = \overrightarrow{AD} = 2\overrightarrow{AO} \).
In the light of the above statements, choose the most appropriate answer from the options given below:
