What is an amphoteric oxide?

Which one of the following orders presents the correct sequence of the increasing basic nature of the given oxides?

Bond enthalpy of $Ge-Ge$ bond is $260 \ kJ \ mol^{-1}$. The bond enthalpies of $Si-Si$ and $Sn-Sn$ bonds in $kJ \ mol^{-1}$ are respectively

Aluminium is diagonally related to (in periodic table)

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A :$ Metallic character decreases and non-metallic character increases on moving from left to right in a period.
Reason $R :$ It is due to increase in ionisation enthalpy and decrease in electron gain enthalpy,when one moves from left to right in a period.
In the light of the above statements,choose the most appropriate answer from the options given below :

In the long form of the periodic table,the $d$-block element which forms an interstitial hydride is