An organism has the following features: diploid ife cycle; protostome embryonic development; true coelom; closed circulatory system; segmentation; appendages without joints; no mantle. To which phylum does this organism belong?

a. Porifera

b. Chordata

c. Mollusca

d. Annelida

e. Arthropoda

Annelida.

Explanation:

The non chordate organisms are classified into 10 different phylum. These organisms are classified into different phylum by looking at the similarities and differences shown by the organism.

The organisms that are involved in the phylum annelids shows the distinguish characteristics of the organisms of other phylum. The organism shows closed circulatory system, body is segmented and no mantle cavity is present. They are true coelomic animal, shows protostomic development in which mouth develops first and anus later. They have appendages that are not jointed with each other.

Thus, the correct answer is option (d).