Answer :
To find the polynomial quotient of (x⁴ + 7x³ + 28x - 16) divided by (x² + 7x - 4), we perform polynomial long division.
```
________________
x² + 7x - 4 | x⁴ + 7x³ + 0x² + 28x - 16
- (x⁴ + 7x³ - 4x²)
____________________
7x³ + 4x² + 28x - 16
- (7x³ + 49x² - 28x)
___________________
53x² - 16
- (53x² - 371x + 236)
__________________
355x - 252
```
The quotient is x² + 4, so the polynomial is option a. x² + 4.