Correct Answer:

Solution : As we move from one box to another, there is a straight line in the middle of the box that increases by one. In the first box, the straight line was one. In the subsequent boxes, it increased to two, three, and four. Therefore, in the next box, the total number of straight lines would be five. Additionally, there is one slant line that cuts across all of these straight lines.
So, the following figure will complete the given series –

Hence, the third option is correct.