A student analyzing the function g finds that g′(2)=0 and g′′(2)=0. The student concludes that x=2 is neither a relative maximum nor a relative minimum of g. Which of the following best evaluates the student’s reasoning?
a) The conclusion is justified because g′′(2)=0 implies the point is an inflection point, so it cannot be an extremum.
b) The conclusion is not justified because g′(2)=0 already ensures the point is an extremum, even though the second derivative test fails.
c) The conclusion is not justified because g′′(2)=0 makes the second-derivative test inconclusive, so additional analysis is required.
d) The conclusion is not justified because g′′(2)=0 guarantees that x=2 is a relative minimum.