Answer:
The answer is A.
Step-by-step explanation:
In order to simplify, you have to collect like terms :
x² - 3xy - 5xy - 7y² + 4x² + 8y²
= (x² + 4x²) + (-3xy - 5xy) + (-7y² + 8y²)
= 5x² - 8xy + y²
