Are the open oceans more rich in silica and iron than land?

Nope. Open oceans are nutrient-poor environments.

Hope this helped,
*Starry*.

Ithink the answer is a or d i hope it my friend message me if i’m wrong and i’ll change my answer and fix it for you

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for