According to the US Centers for Disease Control and Prevention (CDC), your

hands are a primary culprit in the spread of viruses and bacteria. The CDC states
that washing your hands thoroughly with soap and water is the most effective way to
maintain proper hand hygiene. Hand sanitizer containing at least 60 percent alcohol
can be used if you do not have access to soap and water. Either way, having clean
hands will benefit you and others by helping prevent the spread of germs.

What aspect of this argument for proper hand hygiene lends it the most credibility?
By referencing information from the CDC, the writer has provided unbiased research.
By including the 60 percent figure, the writer has provided factual, scientific evidence.
By discussing the spread of germs, the writer has addressed a crucial health concern.

All of the provided aspects contribute to the credibility of the argument for proper hand hygiene. However, referencing information from the CDC provides the most credibility as it is a reputable source known for providing evidence-based information on public health.