The sheet of paper shown in the figure below is folded to form a box

Choose the correct alternative which will represent the position of numbers in above diagram

We make pairs that will be opposite each other after folding

We see that 

a. 1 will be opposite 2

b. 3 will be opposite 5

c. 4 will be opposite 6

Option A - 3 will be opposite 5, hence cannot be adjacent. Wrong

Option B - 4 will be opposite 6, hence cannot be adjacent. Wrong

Option C - 3 will be opposite 5, hence cannot be adjacent. Wrong

Option D - Correct

The correct position is only displayed in Option D