Which of the options critically completes the passage?

Directions: Answer the question based on the following passage.

Many surveys and studies have been conducted asking buyers what traits they value most in sellers. This information is invaluable for those who truly want to be toward the top of the sales profession. Some of the traits buyers say they want to see in sellers are their being: honest, knowledgeable, organized, punctual, solution-oriented, and empathic. For some sellers, these come very naturally, while for others perhaps it’s a constant struggle to exhibit these traits.
Nearly all the traits can be summed up in one word _________.