Final answer:
The ring-tailed lemur is best classified as a Strepsirrhine as it provides a specific and accurate classification within the primate subgroup that includes prosimians like lemurs. Hence, option (D) is correct.
Step-by-step explanation:
The best classification for the ring-tailed lemur would be option D, Strepsirrhines. This classification is the most specific and accurately places the ring-tailed lemur within the correct subgroup of primates. The Order Primates is divided into two groups: the Strepsirrhini and the Haplorhini.
Strepsirrhines are often referred to as "wet-nosed" primates and include prosimians such as lemurs. These animals are typically nocturnal and have a set of distinctive characteristics, like a grooming claw on the second toe and a toothcomb formed by incisors protruding from the mouth.
The ring-tailed lemur, found in Madagascar, belongs to this group. Classifications A (Mammals) and B (Primates) are also correct but too broad, as all lemurs are mammals and primates. Classification C (Lemurs) could be considered correct as well but doesn't specify the ring-tailed lemur's place in the strepsirrhine subgroup, which is more informative about their distinctive traits.