19. The optimizes airflow, keeps cylinder pressure in a certain range, and determines the engine's operating range. O A. push rod
B. valve timing
C. intake manifold
D. valve lift

go to the police department   they will get that person in touch with cps

explanation:

its c because i have that test too

to answer your question:

f(x)= a^x.  if x=0, f(x)=1  if x=1, f(x)=a  if x=1, f(x)=a^a