Consider the following reaction,

$$\begin{gathered} \mathrm{Al}+\mathrm{NaOH}\to \mathrm{X}+{\mathrm{H}}_2 \\ {\mathrm{B}}_2{\mathrm{H}}_6 + {\mathrm{NH}}_3\to \mathrm{Y} \end{gathered}$$

X and Y in the above reaction are-

$$\begin{gathered} 1. \mathrm{X}= \mathrm{Al}{\left(\mathrm{OH}\right)}_2 ; \mathrm{Y} = {\mathrm{N}}_2\left[{\mathrm{BH}}_4\right] \\ 2. \mathrm{X} =\mathrm{Na}\left[\mathrm{Al}{\left(\mathrm{OH}\right)}_4\right] ; \mathrm{Y} ={\mathrm{N}}_3{\mathrm{B}}_3{\mathrm{H}}_6 \\ 3. \mathrm{X}= \mathrm{Na}\left[\mathrm{Al}{\left(\mathrm{OH}\right)}_4\right] ; \mathrm{Y} = {\mathrm{B}}_3{\mathrm{N}}_2 \\ 4. \mathrm{None} \mathrm{of} \mathrm{the} \mathrm{above} \end{gathered}$$

A compound among the following that is least likely to behave as a Lewis base is-
1.  ${\mathrm{NH}}_3$
2.  ${\mathrm{BF}}_3$
3.  ${\mathrm{OH}}^{-}$
4.  ${\mathrm{H}}_2\mathrm{O}$

The correct statement(s) regarding thallium is/are :

1. Thallium displays both +1, and +3 oxidation states.

2. It resembles group 1 metals in some reactions.

3. Thallium only shows a +1 oxidation state.

4. Both (1) and (2)