15. Is the new model even, odd or neither? Explain your reasoning.
A. Even because \( - f ( t ) = f ( t ) \)
B. Even because \( f ( - t ) = f ( t ) \)
C. Odd because \( - f ( t ) = f ( t ) \)
D. Odd because \( f ( - t ) = f ( t ) \)
E. Neither because \( - f ( t ) \neq f ( t ) \) and \( f ( - t ) \neq f ( t )\)