How would you best complete the sentence: Inefficient treatment of customers creates a bad impression of the company?

The completion of the sentence with the phrase "A lack of efficiency negatively impacts" correctly emphasizes the direct relationship between inefficient customer treatment and its consequences for the company’s reputation. This phrase clearly communicates that when a company fails to handle customer interactions efficiently, it leads to negative perceptions by customers, ultimately affecting the company's image.

Focusing on the context, the phrase highlights the importance of efficiency in customer service as a critical aspect of business success. Understanding that customers expect timely and effective service, any failure in this area will likely lead to dissatisfaction and a bad impression, thus reinforcing the relationship established in the original sentence.

The other choices do not align with the intent of the sentence. Phrases that introduce notions of enhancement or positivity (like those implying absence of quality enhances or reflects positively) conflict with the fundamental idea that poor treatment will create a negative impression. The use of "surplus of efficiency affects" also does not fit the negative connotation required, as it suggests a neutral or potentially positive impact instead.