Answer: (C) Competitor
Step-by-step explanation:
According to the given question, Diana's Draperies is basically plush parade's competitors as Diana's Draperies noticing the business of Plush Parade that they designing and then selling the curtains to the customers.
So, they started the same business of Curtains designing and by using the business strategy they start selling the same product at lower price for the purpose of attracting the customers or users in the market.
The competitors is the rival of each other in the business and they usually offering the same products in the market for attracting the consumers in low price for establishing their business.
Therefore, Option (C) is correct answer.