Endospore is formed in

Answer: Option A

Endospore is formed in Gram +ve bacteria.
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota.
The name "endospore" is suggestive of a spore or seed-like form, but it is not a true spore. It is a stripped-down, dormant form to which the bacterium can reduce itself.
Endospore formation is usually triggered by a lack of nutrients and usually occurs in Gram-positive bacteria.