91 more than the square of a number

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Solve the equation using the zero-product property. -3n(7n - 5) = 0 a. 0, -5/7 b. -1/3, -5/7 c. -1/3, 5/7 d. 0, 5/7

Three baby penguins and their father were sitting on an iceberg 0.50.50, point, 5 meters above the surface of the water. the father dove down 4.74.74, point, 7 meters from the iceberg into the water to catch dinner for his kids. what is the father penguin's position relative to the surface of the water?