Easy# Graph of an Odd Function

APCALC-WYHUXG

Given the graph of the odd function $f(x)$ below, which statement must be true?

$I.\ \int _{ a }^{ 0 }{ f( x ) dx=\int _{ 0 }^{ b }{ f( x )dx } } $

$II.\ \int _{ a }^{ b }{ f( x ) dx=0 } $

$III.\ \int _{ a }^{ 0 }{ f( x ) dx=-\int _{ 0 }^{ b }{ f( x )dx } } $