The Law Firm of Ubber & Pratt Received a Very

The Law Firm of Ubber & Pratt received a very large invoice from Court Reporting Agency. Rather than pay the invoice, the firm filed a complaint against the agency hoping that the probability of a long and expensive law suit will frighten them into just forgetting about the invoice. In reality, Ubber & Pratt have no problem with Court Reporting Agency. This tactic

A) violates the rule against bringing a frivolous claim for the purpose of harassment.
B) is a perfectly legitimate and often used method of negotiating the price of services.
C) violates the rule against perpetuity.
D) is a little known method of catching the attention of service providers, and within the boundaries of the law.