For the analysis of iron-phenanthroline complex, the color of the solution a.) becomes more intense as the amount of ferrous ions increases. b.) becomes more intense as the amount of ferric ions...

For the analysis of iron-phenanthroline complex, the color of the solution

a.) becomes more intense as the amount of ferrous ions increases.
b.) becomes more intense as the amount of ferric ions increases.
c.) becomes more intense as the amount of phenanthroline increases.