Let $X = \{ x \mid x > 7 \}$ And $Y = \{ x \mid x \leq - 8 \}$

Multiple Choice

Let $X = \{ x \mid x > 7 \}$ and $Y = \{ x \mid x \leq - 8 \}$ . Determine the given union. Express the answer in interval notal $X \cup Y$

A) $( - \infty , - 8 ] \cup ( 7 , \infty )$
B) $[ - 8,7 )$
C) $( - 8,7 ]$
D) { } .