In a prokaryotic cell, most ribosomes are
a) in the nucleus.
b) attached to the er.
c) attached to the nucleus.
d) floating freely in the cytoplasm.

Correct D). Floating freely in the cytoplasm.

A prokaryote is an organism which does not have the nucleus and almost no membranous organelles. The nucleus is found only in eukaryotes, and each and every cell require ribosomes in order to make proteins.

Since there are no membrane-bound organelles found in prokaryotes, the ribosomes float freely in the cytoplasm.

Hence, the correct answer would be option D.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.