Can someone please help me with one question

Hemoglobin is the compound in red blood cells that carries oxygen to the body. the distribution of hemoglobin in women in g/dl of blood is approximately normally distributed with mean 14 and standard deviation 1. too little hemoglobin, and you're anemic. 2. too much, and (unless you live at high altitudes), you can have other problems.

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above

What is true of sea slugs in these orders