Choose the statement that explains the difference between the
diatom colony and the more advanced spirogyra.

A.The diatom cells are not interconnected and are very similar
to diatoms that are living unicellularly. The spirogyra cells are
the building blocks of the filaments.

B.The diatoms are only photosynthetic thanks to symbiotic algae.
The spirogyra have their own chloroplasts.

C.The diatoms do not have any specialized structures. The
spirogyra have specialized structures, like holdfasts and
leaves.

D.The diatoms are protected by cellulose cell walls. The
spirogyra are protected by silicate shells that could link together
to form several larger structures.