Final answer:
Granny is referring to a petroleum company representative.
Step-by-step explanation:
The man Granny is talking about is a d) petroleum company representative.
This can be inferred from the phrase "That's the fella from the petroleum company was round here last week." Granny specifically mentions that the person is from the petroleum company, indicating that he is a representative of that company.
Based on the given options, only option d) matches the description.