Best Online CAT Coaching

Let the value of n = 2. Then a₁ a₂ + a₂ a₁ = 0
No value of a₁, a₂ will satisfy the above equation.
Hence, option (a) is eliminated. A similar pattern option (b) can also be ruled out to create a zero; we need equal occurrences of 1 and -1, and the total number of terms when n = 3 will be 3. Hence obtaining 0 is not possible.
When n = 4, we can easily obtain 0 when the numbers are 1, -1, 1, -1
Similarly, check for n = 8
Hence, the option (c)