According to me, A. Farming is the most appropriate participle in the sentence.
Explanation:
The reason to the same can be :-
1. Action -In farming some physical activity is taking place which acts as as participle to the sentence.
2. Compound Verb- In English participle are also known to to form compound verb forms that is going, has been etc.
3. Types - Mainly the participle can be divided into three categories that is
