**Core Concept**
Congestive cardiac failure (CCF) in infants is diagnosed based on clinical presentation and physical examination findings, as laboratory tests may not be as sensitive in this age group. **Heart failure** in infants can be due to various causes, including congenital heart defects. The diagnosis often relies on recognizing signs of **cardiac decompensation**.

**Why the Correct Answer is Right**
The correct answer is not provided, however, common signs used to diagnose CCF in infants include tachypnea, tachycardia, hepatomegaly, and poor weight gain. These signs are indicative of **fluid overload** and ** decreased cardiac output**.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option, it's challenging to provide a detailed explanation.
**Option B:** Similarly, without the option, it's difficult to explain why it's incorrect.
**Option C:** And **Option D:** lack specific details to address.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that infants with CCF often present with nonspecific symptoms, making a high index of suspicion crucial for diagnosis.

**Correct Answer:** D. Hepatomegaly and poor weight gain, among other signs.