To determine how much fiber you would consume if you drink half of the smoothie, you first need to find out the total amount of fiber in the entire smoothie.
The smoothie consists of:
- 30 g of fiber
If you drink half of the smoothie, you would consume half of the fiber:
\[ \text{Fiber consumed} = \frac{30 \text{ g}}{2} = 15 \text{ g} \]
Thus, the correct answer is C: 15 grams.