Mature finger grip comes at the age of ___ months.

**Core Concept**
The development of mature finger grip in infants is a significant milestone in motor skill acquisition. It is a complex process involving the maturation of the nervous system, muscle strength, and coordination. The development of finger grip is essential for various activities such as grasping and manipulating objects.

**Why the Correct Answer is Right**
The development of mature finger grip typically occurs between 9 to 12 months of age. This is because the corticospinal tracts, which are responsible for motor control, mature and become more myelinated during this period. Additionally, the muscle strength and coordination of the hands and fingers improve, allowing for a more secure and precise grip. The development of mature finger grip is also influenced by the maturation of the cerebellum, which plays a critical role in motor coordination and balance.

**Why Each Wrong Option is Incorrect**
**Option A:** 3 months - This is too early for the development of mature finger grip, as most infants at this age are still in the process of developing basic hand movements and grasping reflexes.

**Option B:** 6 months - While infants may start to show some improvement in hand movements and grasping at 6 months, mature finger grip typically develops later, around 9-12 months.

**Option C:** 15 months - This is too late for the development of mature finger grip, as most infants are already able to grasp and manipulate objects with precision by this age.

**Clinical Pearl / High-Yield Fact**
Infants typically develop a palmar grasp reflex between 1-3 months of age, which is a primitive reflex that helps them grasp objects. However, this reflex disappears as the infant develops more mature hand movements and coordination.

**Correct Answer:** C. 12 months.