How many $\pi$ electrons are present in naphthalene to decide its aromaticity?

Which among the following is a non-benzenoid aromatic compound?

The electrophile in the nitration of benzene is

$C_6H_6 + 3Cl_2 \xrightarrow{UV \ \text{light}} \text{Product}$. In the above reaction,the product is:

Identify the number of aromatic compounds from the following structures:
$(i)$ $1,2,4$-triazole
(ii) $2$-pyrone
(iii) Benzimidazole
(iv) Pyrazole
$(v)$ Cyclooctatetraene dianion
(vi) Pyrrolidinium cation
(vii) Cyclopentadienyl cation

In the following reaction,
$CH_3-C \equiv CH \xrightarrow[873 \ K]{\text{red hot iron tube}} A$
the number of sigma$(\sigma)$ bonds present in the product $A$ is