**Core Concept**
Anticipation is a phenomenon where a disease or condition manifests at an earlier age than expected, often in successive generations. This concept is particularly relevant in the study of genetics and the understanding of the inheritance of diseases.

**Why the Correct Answer is Right**
Anticipation occurs due to the expansion of trinucleotide repeat sequences within genes, leading to an increased number of repeats in subsequent generations. This expansion results in a more severe expression of the disease, often at an earlier age. The most common example of anticipation is seen in Huntington's disease, where the age of onset tends to decrease with each successive generation. The expansion of CAG repeats in the huntingtin gene is responsible for the earlier age of onset and increased severity of the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the concept of anticipation, as it is more related to the concept of regression.
**Option B:** This option is incorrect because it is more related to the concept of compensation, where the body tries to adapt to a loss or damage.
**Option C:** This option is not directly related to the concept of anticipation, although it may be related to other genetic concepts.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that anticipation is often seen in trinucleotide repeat disorders, such as Huntington's disease, and is characterized by an earlier age of onset in successive generations.

**Correct Answer:** D.