It is c I believe cause the human cells can’t make their own food like plants do when they photosynthesis
)Sexual reproduction maintains a constant level of variation in the population and requires less energy.
Arthropoda and molluscs have open circulatory systems - meaning haemolymph (Their equivalent to blood) directly bathes the tissue, and isn't enclosed in blood vessels, as seen in a closed blood system, as in humans for example.
