During Height and Weight Assessments at a School's Health Fair

During height and weight assessments at a school's health fair, a child admits to drinking a cup of coffee with his mother every morning, and another child reports enjoying a morning cup of coffee on the commute to school. These two children are both below average on the height chart, and the nurse states, "Drinking coffee stunts a child's growth." This logical fallacy is referred to as:

A) appeal to common practice.
B) confusing cause and effect.
C) ad hominem abusive.
D) red herring.