Identify the element having the smallest ionic size in the $+3$ state from the following.

Which of the following elements belongs to the inner transition elements?

Lanthanides and actinides resemble in

Identify the element with the smallest ionic radius in the $+3$ oxidation state from the following:

Which of the following statements is incorrect with reference to $Ce$ $(Z=58)$?

The correct statements among the following are:
$A$. $Mo(VI)$ and $W(VI)$ are less stable than $Cr(VI)$.
$B$. $Ce^{4+}$ and $Tb^{4+}$ are oxidants,while $Eu^{2+}$ and $Yb^{2+}$ are reductants.
$C$. $Cm$ and $Am$ have seven unpaired electrons.
$D$. Actinoid contraction is greater from element to element than lanthanoid contraction.
Choose the correct answer from the options given below: