Study the given pattern carefully and select the number that can replace the question mark (?) in it.

Logic: Divide the sum of the numbers given at the vertice of the triangle by 3 to get the number in the middle of the triangle.

Figure 1: (3 + 6 + 12) $$\div$$ 3 = 21 $$\div$$ 3 = 7

Figure 2: (7 + 4 + 13) $$\div$$​ 3 = 24 $$\div$$​ 3 = 8

Figure 3: (5 + 4 + 3) $$\div$$ 3 = 12 $$\div$$ 3 = 4

Thus, the correct answer is (d).​​