P Chromatophora Secretes Around Itself a Test, or Case, of Plates

Multiple Choice

P. chromatophora secretes around itself a test, or case, of plates made of silica. Which of the following is another rhizarian that would be in competition with P. chromatophora for the silica needed to make these plates, assuming limited quantities of silica in the environment?

A) radiolarians
B) foraminiferans
C) all other amoeboid cells
D) all other rhizaria
E) diatoms