The answer to the question is the sales response curve approach.
The ABC Company is searching for an analytical technique to evaluate its impending customer service decision. Of the analytical techniques mentioned, only the sales response curve approach is applicable in this case. The reason is that the sales response curve approach deals with sales response to various pricing, promotional, and service scenarios.
Therefore, it can help ABC Company in deciding whether to change its customer service strategy. By employing the sales response curve approach, ABC Company can test different service scenarios and find out which scenario provides the most significant positive impact on sales. The sales response curve approach applies in the case of ABC Company.