The number of statement$(s)$ correct from the following for copper (atomic number $29$) is/are $...$
$(A) \ Cu(II)$ complexes are always paramagnetic
$(B) \ Cu(I)$ complexes are generally colourless
$(C) \ Cu(I)$ is easily oxidized
$(D)$ In Fehling solution,the active reagent has $Cu(II)$

The transition metals have a less tendency to form ions due to

Given below are two statements:
Statement $I$: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is $3$: $[Sc^{3+}, Ti^{3+}], [Mn^{2+}, Cr^{2+}], [Cu^{2+}, Zn^{2+}]$ and $[Ni^{2+}, Ti^{4+}]$.
Statement $II$: $Th^{4+}$ is the strongest reducing agent among $Th^{4+}, Ce^{4+}, Gd^{3+}$ and $Eu^{2+}$.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following orders is correct?

Which of the following transition metals is used as a catalyst?

Match the items in Column-$I$ with the items in Column-$II$.

Column-$I$	Column-$II$
$(1)$ General electronic configuration of $d$-block elements	$(A)$ Transition elements
$(2)$ $d$-block elements	$(B)$ $(n-1)d^{1-10}ns^{1-2}$
$(3)$ Groups $3$ to $12$	$(C)$ $Z = 58$ to $71$
$(4)$ Lanthanoid elements	$(D)$ Last electron enters $d$-orbital