Answer
(x²)² + 5(x²) - 6
Option B is correct.
Then, when we make the substitution, a = x², the expression becomes
(a)² + 5(a) - 6
Option A is correct.
Explanation
The expression is
x⁴ + 5x² - 6
we can then put this in quadratic expression form
(x²)² + 5(x²) - 6
Option B
Then, when we make the substitution, a = x², the expression becomes
(a)² + 5(a) - 6
Option A
Hope this Helps!!!