Select the equivalent expression. \left(6^{-4}\cdot 8^{-7}\right)^{-9}=?(6 −4 ⋅8 −7 ) −9 =?left parenthesis, 6, start superscript, minus, 4, end superscript, dot, 8, start superscript, minus, 7, end superscript, right parenthesis, start superscript, minus, 9, end superscript, equals, question mark Choose 1 Choose 1 (Choice A) A 6^{36}\cdot 8^{63}6 36 ⋅8 63 6, start superscript, 36, end superscript, dot, 8, start superscript, 63, end superscript (Choice B) B 6^{5}\cdot 8^{2}6 5 ⋅8 2 6, start superscript, 5, end superscript, dot, 8, squared (Choice C) C \dfrac{1}{6^{13}\cdot 8^{16}} 6 13 ⋅8 16 1