Let the equation $\mathrm { x } ^ { 4 } - \mathrm { ax } ^ { 2 } + 9 = 0$ have four real and distinct roots. Then the least integral value of $a$ is (A) 5 (B) 7 (C) 6 (D) 8
Let the equation $\mathrm { x } ^ { 4 } - \mathrm { ax } ^ { 2 } + 9 = 0$ have four real and distinct roots.
Then the least integral value of $a$ is\\
(A) 5\\
(B) 7\\
(C) 6\\
(D) 8