Sketch the Graph of the Function and Determine Whether It $x = 0$

Sketch the graph of the function and determine whether it has any absolute extreme values on its domain.
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A) no absolute maximum;
no absolute minimum


B) absolute maximum at $x = 0$ and $x = 2 \pi$ ;
absolute minimum at $x = \pi$


C) no absolute maximum;
absolute minimum at $x = \pi$


D) absolute maximum at $x = 0$ ; absolute minimum at $x = \pi$