Bleaching action of $SO_2$ is due to

Elements of group $16$,except $Po$,are known as chalcogens because .........

Given below are two statements:
Statement $I$: Oxygen being the first member of group $16$ exhibits only $-2$ oxidation state.
Statement $II$: Down the group $16$ stability of $+4$ oxidation state decreases and $+6$ oxidation state increases.
In the light of the above statements,choose the most appropriate answer from the options given below:

In which of the following arrangements is the given sequence not strictly according to the property indicated against it?

Which of the following elements exhibits the highest property of catenation?

Anomalous behaviour of oxygen is due to its