The Local Maximum for the Function $f(x)=8 X_{3}+2 X_{2}-4 X-3$ Is Obtained When

Multiple Choice

The local maximum for the function $f(x) =8 X_{3}+2 X_{2}-4 X-3$ is obtained when $X$ is equal to

A) 1
B) -1
C) $5 / 6$
D) $1 / 6$