Hello there!
Your question asks what managerial task Marietta is performing from what she said.
Answer: C). Planning
The reason why answer choice "C). Planning" is the correct answer because this is what she's specifically performing. The way she is performing planning is that she noticed that there was a increase in demand of the rhinestone jewelry, so she is going to plan out how she's going to get the rhinestone jewelry in the company's stores.
Also, she's planning all of the organizational resources in order to make sure that her idea works and helps the business become successful in profits, since not a lot of businesses are selling the rhinestone jewelry. She needs to plan out how she's going to attain the resource, the rhinestone, and complete her goal by selling it in the stores.
I hope this helps!
Best regards,
MasterInvestor