Since the function and choices are already given, the simplest method would be to try out the given values of x and see if the value of y obtained and given int he choices would coincide. Using this trial and error method, it has been shown that the correct answer among the choices is choice C, with the solution shown below:
y = -0.296x^2 + 2.7x
Using (4.6, 6.2):
y = -0.296(4.6)^2 + 2.7(4.6)
y = 6.2