Solution :
In $$A{l_2}{O_3},S{b_2}{O_3},B{i_2}{O_3}$$ and $$Se{O_2},B{i_2}{O_3}$$ is most basic oxide. As across the period basic nature of oxide decreases and on moving down the group it increases.
$$B{i_2}{O_3} + 6HCl \to 2BiC{l_3} + 3{H_2}O$$
Releted MCQ Question on Inorganic Chemistry >> P - Block Elements
Releted Question 1
The reddish brown coloured gas formed when nitric oxide is oxidised by air is