Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
\[
\text{Assertion (A): Shankaracharya believed the world to be a mere appearance.}
\]
\[
\text{Reason (R): He believed that Brahman is the only absolute reality.}
\]
In the light of the above statements, choose the most appropriate answer from the options given below: