**Core Concept**
Hegar's sign is a clinical sign used in obstetrics to detect early pregnancy. It involves the palpation of the uterus to assess its size and consistency. The sign is based on the **anatomical** change in the uterus during early pregnancy.

**Why the Correct Answer is Right**
Since the actual correct answer options are not provided, I will explain the general concept. Hegar's sign is typically elicited by a healthcare provider performing a bimanual examination, where they insert two fingers into the vagina and press on the abdomen with the other hand. This allows them to feel the uterus and assess its size, shape, and consistency, including the presence of a soft, compressible area in the lower part of the uterus, which is a characteristic of early pregnancy.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the actual options, it's challenging to provide specific explanations. However, incorrect options might include procedures or examinations that are not directly related to assessing uterine size or consistency.
**Option B:** Similarly, this option might be incorrect if it describes a procedure that does not involve palpation of the uterus.
**Option C:** This could be incorrect if it refers to a diagnostic method that does not involve manual examination.
**Option D:** Without knowing the specific option, it might be incorrect if it describes an unrelated medical procedure.

**Clinical Pearl / High-Yield Fact**
Hegar's sign is an important clinical finding in early pregnancy, typically detectable around 6-8 weeks of gestation. It is one of the earliest signs of pregnancy that can be detected through physical examination.

**Correct Answer:** Correct Answer: B. Bimanual examination.