Answer:
a. eutherian
Step-by-step explanation:
Eutherian are a group of extant mammals that bear their young alive, and most especially nurture their young one during pregnancy as they possess placenta, which serves as a structure for the passage of nutrients from the mother to the young one in the uterus. Eutherians give birth to their young when they are fully developed.
The description given in the question about this newly recognized species known as olinguito, is most likely to be considered a eutherian. Raccoons are also eutherians, apparently the new species should also be a eutherian.