C) Apparent and inapparent
According to this concept, disease in a community may be compared with an iceberg. The floating tip of the iceberg represents what the physician sees in the communily, i.e., clinical cases. The vast submerged portion of the iceberg represents the hidden mass of disease, i.e., latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community. The "waterline" represents the demarcation between apparent and inapparent disease.
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