Answer:
19
Explanation:
To find the answer, you can look for a pattern in how the numbers are being added together.
If you take the first number in each set (1, 2, 8), and add 1 to it, you get the second number in that set (4, 7, 11).
Then, if you add 1 to the second number in each set (5, 12), you get the third number in that set.
Using this pattern, you can find the answer to the question:
d. 8 + 11 = 19
Therefore, the answer is 19.