\[\boxed{\mathbf{203.}}\]
\[C = \left\{ a;o;d;q \right\};\ \ D = \left\{ p;o;t;q \right\}.\]
\[\textbf{а)}\ C \cap D = \left\{ o;q \right\}.\]
\[\textbf{б)}\ C \cup D = \left\{ a;o;d;q;p;t \right\}.\]