How is e. coli like a paramecium
a both produce essential viatimins
b both are unicellular
c both have a contractive vacuole d both have a nucleoid

The answer is B both are unicellular.

E. coli and paramecium are both unicellular. And that is their only common characteristic. E. coli is a prokaryotic unicellular organism while paramecium is a eukaryotic unicellular organism. So, paramecium has nucleus and E.coli has a nucleoid. Neither of them produce essential vitamins. Contractive vacuoles are present only in paramecium.