A.\(k = 1\)
B.\(k = \dfrac{{2017.\sqrt {2018} }}{2}\)
C.\(k = \dfrac{{2016}}{{2017}}\sqrt {2019} \)
D.\(k = 2\sqrt {2019} \)

A.\(0\)
B.\( + \infty \)
C.\(\dfrac{1}{2}\)
D.\( - \infty \)

A.\(m =  - 3\)
B.\(m =  - 1\)
C.\(m = 0\)
D.\(m = 3\)

A.\(\dfrac{4}{{15}}\)
B.\(\dfrac{{12}}{{25}}\)
C.\(\dfrac{6}{{25}}\)
D.\(\dfrac{4}{{25}}\)

A.\(\left( {0;1} \right)\)
B.\(\left( {1;2} \right)\)
C.\(\left( { - 1;0} \right)\)
D.\(\left( {2;3} \right)\)

A.\(\Delta //BC\)
B.\(\Delta //AB\)
C.\(\Delta //AC\)
D.\(\Delta //AA'\)

A.\(1\)
B.\( - 2\)
C.\(0\)
D.\( - 1\)

A.\(\dfrac{{n - 1}}{{m - 1}}\)
B.\(\dfrac{n}{m}\)
C.\(\dfrac{{n + 1}}{{m + 1}}\)
D.\(\dfrac{{n!}}{{m!}}\)

A.Hình thang
B.Hình tam giác
C.Hình ngũ giác
D.Hình lục giác

A.\( - 2\)
B.\(0\)
C.\(1\)
D.\( - 1\)