Determine the Maximum Possible Number of Turning Points for the Graph

Multiple Choice

Determine the maximum possible number of turning points for the graph of the function.
-The profits (in millions) for a company for 8 years were as follows:

Which of the following polynomials is the best model for this data?

A) $P ( x ) = 0.05 x ^ { 2 } - 0.8 x + 6$
B) $P ( x ) = - 0.08 x ^ { 3 } + 7 x ^ { 2 } + 1.3 x - 0.18$
C) $P ( x ) = 0.03 x ^ { 3 } - 0.3 x ^ { 2 } + 1.3 x + 0.17$
D) $P ( x ) = - 0.03 x ^ { 4 } - 0.3 x ^ { 2 } + 1.3 x + 0.17$