The two grids A and B given below follow a certain pattern.

Analyze the chevron diagonal pattern indicated by the colored lines in both grids:

1. Grid A (Red Chevron):

   • The red chevron connects:
     • Top-Left cell: $3$
     • Center cell: $2$
     • Bottom-Left cell: $3$
   • Sum of the chevron vertices:
     $$3 + 2 + 3 = 8$$
   • Notice that $8$ is exactly the value in the middle-left cell (Row 2, Column 1).

2. Grid B (Green Chevron):

   • The green chevron connects:
     • Top-Left cell: $4$
     • Center cell: $4$
     • Bottom-Left cell: $2$
   • Applying the identical chevron vertex summation rule to find the missing middle-left cell '?':
     $$? = 4 + 4 + 2 = \mathbf{10}$$

Thus, the missing number '?' is 10 (Option B).