Which group includes microorganisms that lack a defined nucleus but contain genetic material (nucleoid)?

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Halophiles	$(p)$ Gram-positive bacteria
$(B)$ Firmicutes	$(q)$ Hot springs habitat
$(C)$ Methanogens	$(r)$ Gram-negative bacteria
$(D)$ Spirochetes	$(s)$ Photosynthetic bacteria
$(E)$ Thermoacidophiles	$(t)$ Extremely salty areas habitat
	$(u)$ Responsible for biogas production

Match the following columns:

Column-$I$	Column-$II$
$(A)$ Halophiles	$(I)$ Gram-negative bacteria
$(B)$ Thermoacidophiles	$(II)$ Inhabit extremely salty areas
$(C)$ Spirochaetes	$(III)$ Responsible for methane production
$(D)$ Firmicutes	$(IV)$ Survive in acidic and high-temperature conditions
	$(V)$ Gram-positive bacteria

What type of microorganism is $Oscillatoria$?

Organisms which have cells but no distinct nucleus are known as:

Refer to the given figures of a bacterial cell and Nostoc and choose the option which shows the correct labels for the structures marked as $A$,$B$,$C$,$D$,and $E$.