Which of the following statements about open systems as given by Daniel Katz and Robert Khan are true?
1. The exportation of energic inputs into the environment.
2. Transformation of available energy as through put, so that work is done.
3. The importation of the output from the environment.
4. A cycle of events in which the product exported to the environment provides the energy for repetition of the cycle.

A. 1, 2

B. 2, 3

C. 2, 4

D. 1, 4

Answer: Option C