Answer:
B. is a price taker
Step-by-step explanation:
A single-price monopoly can be described as a monopolist that must sell to all its customers at the same price each unit of its product.
A single-price monopolist is different from a price-discriminating monopoly that can different unit of its output at different prices.
Therefore, a single-price monopoly is a price taker because it has no power to price discriminate.