**Core Concept**
Glycine is a crucial amino acid involved in the synthesis of purine nucleotides. It acts as a precursor for several steps in the purine biosynthetic pathway, which ultimately leads to the formation of adenine and guanine nucleotides. This process is essential for DNA and RNA synthesis.

**Why the Correct Answer is Right**
Glycine provides the carbon atoms 4 and 5, and the nitrogen atom 7 of the purine ring through a series of enzyme-catalyzed reactions. The first step in purine synthesis is the formation of 5-phosphoribosyl-1-pyrophosphate (PRPP), which is then converted to 5-phosphoribosylamine (PRA) with the help of glycine. Glycine is then incorporated into the purine ring through the action of the enzyme glycinamide ribonucleotide synthetase (GAR synthetase). This enzyme catalyzes the reaction between PRA and glycine to form glycinamide ribonucleotide (GAR). GAR is then converted to formylglycinamide ribonucleotide (FGAR), which eventually leads to the formation of the purine ring.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because we do not have enough information to assess it.
**Option B:** This option is incorrect because it is not related to the question of glycine's role in purine synthesis.
**Option C:** This option is incorrect because it is not a correct statement about glycine's role in purine synthesis.

**Clinical Pearl / High-Yield Fact**
Glycine is also involved in the synthesis of creatine, a high-energy compound found in muscle tissue. The biosynthesis of creatine from glycine is an important pathway that is often disrupted in patients with creatine deficiency syndromes.

**Correct Answer: A.**