Which of the following is a tool that can assess the impact of pain on daily activities?

Quality of life scales are specifically designed to evaluate how various health issues, including pain, affect a person's daily activities and overall well-being. These scales incorporate subjective measures that assess physical, emotional, and social functioning, helping to capture the nuanced ways that pain can impact a person's life.

In contrast, blood tests, X-rays, and allergy tests are primarily diagnostic tools used to identify specific medical conditions or physiological abnormalities. While they can provide important information related to pain, they don’t directly measure the impact of pain on an individual’s daily activities or quality of life. Therefore, quality of life scales are the most relevant tool for understanding how pain affects a person's daily functioning.