Mark the tick against the correct answer in the following:
To find: Value of 
We have, 
Applying 
⇒ 
Applying 
⇒ 
Expanding along C3
⇒ [1{(a2-1)(a-1) – (a-1)(2a – 2)}]
⇒ [1{(a-1)(a+1)(a-1) – (a-1)2(a – 1)}]
⇒ [{(a+1)(a-1)2 – 2(a-1)2}]
⇒ [{(a-1)2 (a+1-2)}]
⇒ [{(a-1)2 (a-1)}]
⇒ (a-1)3
1