Mathematics

Problem

1. Decide, among the following sets, which sets are subsets of one and another:

\mathrm{A}=\left\{x: x \in \mathbf{R}\right.

and

x

satisfy

\left.x^{2}-8 x+12=0\right\}

\mathrm{B}=\{2,4,6\}, \quad \mathrm{C}=\{2,4,6,8, \ldots\}, \mathrm{D}=\{6\}