Answer:
3%
Step-by-step explanation:
The total energy ingested is 3000J and of those 3000J, 100J are used for growth and reproduction, this is the part of production in the porcupine, since the other 800J and 2100J are used for internal processes of the porcupine.
Therefore the production efficiency is 100J of the 3000J, let's find out how much it is in percentage:

⇒0.033=3.3% ≈ 3%
The correct option es 3% of production efficiency.