Answer:
I think b.
Explanation: The mineral composition of manganese-bearing minerals is dependent on how the nodules are formed; sedimentary nodules, which have a lower Mn 2+ content than diagenetic, are dominated by Fe-vernadite, Mn-feroxyhyte, and asbolane-buserite while diagenetic nodules are dominated by buserite I, birnessite, todorokite, and asbolane-buserite. The growth types …
