Final answer:
In annelids like earthworms, the oldest segments are located at the anterior end, as new segments are added sequentially at the posterior end near the pygidium through teloblastic growth.
"The correct option is approximately option A"
Step-by-step explanation:
The question focuses on determining the age of segments in annelids, such as earthworms, which are part of the phylum Annelida and exhibit a segmented body plan known as metamerism. Metamerism means that internal and external features are replicated in each body segment.
The evolutionary development of annelids involves the addition of new segments at the posterior end, near the pygidium. This growth pattern is called teloblastic growth, which facilitates the sequential development of new segments after the head.
Given this information on the growth process of annelids, we can deduce that the oldest segments would be located at the anterior end, closest to the head, where the earliest segments were formed. Conversely, the newest segments would be at the posterior end, where recent growth has occurred. Therefore, when considering the age of segments of an annelid such as an earthworm, the statement that fits best is:
(a) The oldest segments are at the anterior end.