**Core Concept**
Formocresol is a mixture of formaldehyde and cresol, used in pediatric dentistry for pulp capping and pulpotomy procedures. The ratio of formalin (formaldehyde solution) to cresol in formocresol is critical for its effectiveness and safety.

**Why the Correct Answer is Right**
The correct ratio of 1:2 (formalin:cresol) in formocresol allows for the optimal balance of formaldehyde's antimicrobial properties and cresol's solubility and stability. Formaldehyde's rapid action against bacteria and fungi is complemented by cresol's ability to dissolve and stabilize the mixture, making it suitable for use in pediatric dental procedures. This ratio has been extensively studied and validated for its efficacy and safety profile.

**Why Each Wrong Option is Incorrect**
**Option A:** The 3:0.2 ratio is too concentrated in formalin, which may lead to tissue irritation and toxicity.
**Option B:** The 2:0.3 ratio is too diluted in cresol, which may compromise the mixture's antimicrobial efficacy.
**Option D:** The 2:1 ratio is too high in formalin, which may cause excessive tissue damage and toxicity.

**Clinical Pearl / High-Yield Fact**
The American Academy of Pediatric Dentistry recommends using a 1:2 ratio of formocresol for pulpotomy procedures in primary teeth to minimize tissue irritation and maximize antimicrobial efficacy.

**✓ Correct Answer: C. 1:02**