Let $$\begin{array} { l } U = \{ 1,2,3,4,5,6,7 \} \\A = \{ 1,2,4,5 \} \\B = \{ 1,2,3,6 \} \\C = \{ 4,6,7 \}\end{array}$$

Multiple Choice

Let $$\begin{array} { l } U = \{ 1,2,3,4,5,6,7 \} \\A = \{ 1,2,4,5 \} \\B = \{ 1,2,3,6 \} \\C = \{ 4,6,7 \}\end{array}$$ List all the members of the set. $A \cup B$

A) $\{ 1,2,3,6 \}$
B) $\{ 1,2,4,5 \}$
C) $\{ 1,2 \}$
D) $\{ 1,2,3,4,5,6 \}$
E) $\varnothing$