Answer:
B-Capsule
Step-by-step explanation:
Bacteria from Yersinia genus don't develop capsules, but Yersinia pestis has the exception. Y.pestis develops a similar structure to a capsule.
Other options are true for Y.pestis and all Yersina genus. Despite the fact that someones can lose their motility in a stage of their life cycle, these bacteria are motile. Also, they are facultative anaerobic organisms and they don´t form spores.