**Core Concept**
The transport of long-chain acyl-CoA across the mitochondrial inner membrane is a crucial step in the regulation of fatty acid oxidation. This process involves a specific transporter to facilitate the movement of these molecules into the mitochondria.

**Why the Correct Answer is Right**
The correct answer is Carnitine-Palmitoyltransferase 1 (CPT1). CPT1 is a transmembrane enzyme that catalyzes the transfer of the acyl group of long-chain acyl-CoA to carnitine, forming acyl-carnitine. This reaction is essential for the transport of long-chain acyl-CoA into the mitochondria, where they can undergo beta-oxidation. CPT1 is primarily located on the outer mitochondrial membrane and is tightly regulated by various factors, including the energy status of the cell.

**Why Each Wrong Option is Incorrect**
**Option A:** Carnitine-Palmitoyltransferase 2 (CPT2) is involved in the transfer of long-chain acyl-CoA out of the mitochondria, not into the mitochondria.

**Option B:** Acyl-CoA synthetase is involved in the activation of fatty acids to form acyl-CoA, but it is not directly involved in the transport of long-chain acyl-CoA into the mitochondria.

**Option C:** Acyl-carnitine translocase is involved in the transport of acyl-carnitine across the mitochondrial inner membrane, but it is not the primary enzyme responsible for the transport of long-chain acyl-CoA into the mitochondria.

**Clinical Pearl / High-Yield Fact**
CPT1 is a key regulatory enzyme in the transport of long-chain acyl-CoA into the mitochondria, and its activity is tightly regulated by various factors, including malonyl-CoA, which is an inhibitor of CPT1.

**Correct Answer:** C. Carnitine-Palmitoyltransferase 1 (CPT1)