**Core Concept**
The pectoralis major muscle receives its blood supply from branches of the thoracoacromial and lateral thoracic arteries, providing a dual blood supply to the muscle. This is essential for the muscle's function and overall health.

**Why the Correct Answer is Right**
The thoracoacromial artery, a branch of the axillary artery, divides into four branches: the pectoral, deltoid, acromial, and clavicular branches. The pectoral branch supplies the pectoralis major muscle, making it the primary source of blood supply. Additionally, the lateral thoracic artery, a branch of the axillary artery, also contributes to the blood supply of the pectoralis major muscle, especially its lateral aspect. This dual blood supply allows for a robust vascular network, enabling the muscle to perform its functions effectively.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a correct answer as it does not specify the correct artery.
**Option B:** Not a correct answer as it does not accurately describe the primary blood supply to the pectoralis major muscle.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the pectoralis major muscle receives its blood supply from two main arteries, the thoracoacromial and lateral thoracic arteries. This dual blood supply is crucial for the muscle's function and overall health.

**Correct Answer: C. Thoracoacromial and lateral thoracic arteries.**