A. Electronic configuration of americium →[Rn]5f7.7s2 B. Bm of Sm3+,La3+ and Gd3+→5.9,0.0,7.94‌as these have 5,0 and 7 unpaired electrons in their outermost shell. (Element belongs to f -block). C. TiCl4
H2OTiO2
─────▸
i.e. on hydrolysis TiCl4 give TiO2 D. Hg2Cl2
aqua−regia
─────▸
Corrosive sublimate ∴ Hence, (d) is the correct option.