Explanation:

- The given code language seems to follow a pattern where each number is transformed before addition.

- In the first example, 23 + 49 = 278. This suggests that 23 becomes 2 and 49 becomes 7, followed by 8.

- In the second example, 24 + 51 = 410. It seems that 24 becomes 4 and 51 becomes 10, possibly summing to 4 + 10.

- For 78 + 61, let's apply a similar pattern: 78 could become 8, and 61 could become 4, forming the result 84.

- This aligns with Option 3, which is 842.

?