If x = 3.2 × 10.24 + 7.84 × 2.8 + 9.6 × 8.96 + 23.52 × 3.2, then √x is equal to:

Let a = 3.2 and b = 2.8.
Notice that 10.24 = (3.2)² = a² and 7.84 = (2.8)² = b².

Let's break down the given expression for x:
Term 1: 3.2 × 10.24 = a × a² = a³
Term 2: 7.84 × 2.8 = b² × b = b³
Term 3: 9.6 × 8.96 = (3 × 3.2) × (3.2 × 2.8) = 3 × a × (ab) = 3a²b
Term 4: 23.52 × 3.2 = (3 × 7.84) × 3.2 = 3 × b² × a = 3ab²

The expression simplifies to: x = a³ + b³ + 3a²b + 3ab²
This is the standard algebraic identity for (a + b)³.
So, x = (3.2 + 2.8)³ = (6)³ = 216.

We need to find √x:
√x = √216 = √(36 × 6) = 6√6.

Final Answer: Option C