The diagram illustrates how energy moves through an ecosystem. Photosynthesis is the gross productivity. Producers lose some energy through respiration, and the energy that remains is the net productivity. This may also be written as an equation: $\text{net productivity} = \text{gross productivity} - \text{respiration}$ Some of the net productivity is transferred to herbivores. Which calculation shows the proportion of net productivity transferred to herbivores?
- A$\frac{0.075}{1.8}$
- B$\frac{0.75}{1.8}$
- C$\frac{0.75}{4.0}$
- D$\frac{0.75 + 0.075}{1.8}$