**Core Concept**
The presence of heart disease in pregnancy can be indicated by various signs and symptoms that differ from those seen in normal pregnancy. This is crucial for timely diagnosis and management to prevent adverse outcomes for both mother and fetus.

**Why the Correct Answer is Right**
The correct answer is **B. Systolic ejection murmur**. In pregnancy, an increase in cardiac output and blood volume can lead to the development of a systolic ejection murmur due to increased flow across the aortic valve. This is a common finding in normal pregnancy and does not necessarily indicate the presence of heart disease. However, in the context of pregnancy, a systolic ejection murmur can also be a sign of aortic stenosis or other valvular heart diseases.

**Why Each Wrong Option is Incorrect**
* **Option A:** A new onset of pedal edema in pregnancy is not necessarily indicative of heart disease. While edema can be a sign of fluid overload, it can also be caused by other factors such as venous insufficiency or pre-eclampsia.
* **Option C:** A change in the character of the second heart sound (S2) during pregnancy can indicate the presence of heart disease. A split S2 can be a sign of increased flow across the pulmonary valve, which can be seen in conditions such as mitral regurgitation or aortic regurgitation.

**Clinical Pearl / High-Yield Fact**
In pregnancy, a systolic ejection murmur can be a normal finding, but it's essential to consider the patient's overall clinical context, including heart rate, blood pressure, and symptoms, to determine the underlying cause.

**Correct Answer: B. Systolic ejection murmur**