Which of the following is a free-living,aerobic,non-photosynthetic,nitrogen-fixing bacterium?

The cells of the bacterium $Streptococcus$ remain arranged in the form of

Read the following statements:
$A.$ Mango is included under order 'Poales'.
$B.$ Chemosynthetic autotrophic bacteria oxidize various inorganic substances such as nitrite and ammonia and use the released energy for their $ATP$ production.
$C.$ Members of Ascomycetes are parasitic only.
$D.$ In one citric acid cycle,$2 NADH_2$ and $1 FADH_2$ are formed.
$E.$ Pyruvic acid $+ CoA + NAD^+ \xrightarrow{\text{Pyruvate dehydrogenase}} \text{Acetyl } CoA + CO_2 + NADH + H^+$.
Choose the correct option:

Which kingdom is included in the five-kingdom classification system?

Which type of cell division occurs in $Nostoc$?

The mode equivalent to sexual reproduction in bacteria is: