The forward differences for this data is 1, 1, 1, 1, 1, 1 (since 10 - 9 = 1, 11 - 10 = 1, etc). Since we only need one iteration of differences, a linear polynomial will fit the data exactly.
I think its b, i hope this is the rigth answer this was a little tough...
]Answer:

Step-by-step explanation:
Substitute the value of the variable into the equation and simplify.

Solve it out.
Multiply / divide / add / subtract everything out.