Which element from the following is the last element of the $5d$-transition series?

Most stable cation in aqueous medium is

The general electronic configuration of the transition elements is

Transition metal ions form interstitial compounds because...

Number of paramagnetic ions among the following $d$- and $f$-block metal ions is . . . . . . . $Mn^{2+}$,$Cu^{2+}$,$Zn^{2+}$,$Yb^{2+}$,$Sc^{3+}$,$La^{3+}$,$Gd^{3+}$,$Lu^{3+}$,$Ti^{4+}$,$Ce^{4+}$. (Atomic number of $Mn = 25$,$Cu = 29$,$Zn = 30$,$Yb = 70$,$Sc = 21$,$La = 57$,$Gd = 64$,$Lu = 71$,$Ti = 22$,$Ce = 58$)

Which of the following is the correct sequence of atomic weights of the given elements?