Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : In TlI₃, isomorphous to CsI₃, the metal is present in +1 oxidation state.

Reason R : Tl metal has fourteen f electrons in its electronic configuration.

In the light of the above statements, choose the most appropriate answer from the options given below :

Which of the following forms of hydrogen emits low energy $$\beta$$^- particles?

Which pair of oxides is acidic in nature?

Identify A in the given reaction.