Q: The heart is a muscular organ that pumps blood through which system?


Read this paragraph and choose the correct option from the provided answers:

Mollusks have a circulatory system with one or two hearts that pump blood. The heart is a muscular organ that pumps blood through the circulatory system when its muscles contract. The circulatory system may be open or closed, depending on the species.

 Choices:

- endocrine

- pulmonary

- nervous

- circulatory


A:
circulatory