Statement A is true as all group 16 elements form \(EO_2\) and \(EO_3\) oxides, and these oxides are generally acidic.
Statement B is true as \(TeO_2\) acts as an oxidising agent, while \(SO_2\) is a reducing agent.
Statement C is false. The reducing nature actually increases as we move down the group.
Statement D is false as the ozone molecule \(O_3\) contains only three lone pairs of electrons on each oxygen atom.
Let $ a_1, a_2, a_3, \ldots $ be in an A.P. such that $$ \sum_{k=1}^{12} 2a_{2k - 1} = \frac{72}{5}, \quad \text{and} \quad \sum_{k=1}^{n} a_k = 0, $$ then $ n $ is: