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

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Correct option is B

Given:

Logic: $$\frac{\text{Product of the lower Circle}}{2}$$ = Upper Circle

In Figure 1st:

$$\frac{6 \times 7}{2}$$ = 21

In Figure 2nd:

​$$\frac{3 \times 8}{2}$$​ = 12

Similarly, 

In Figure 3rd:

​$$\frac{7 \times 2}{2}$$​ = 7

Thus, the correct option is (b) 7