Explanation:

- The relationship between the numbers in the given set (11, 165, 209) is sequential and involves multiples and addition.

- Multiply 11 by a number to get 165: $11\times 15=165$.

- Add a number to get 209: $165+44=209$.

- Option 1: (14, 210, 276)

- Calculate $14\times 15=210$.

- Calculate $210+66=276$.

- The additional number is not the same as in the original set.

- Option 2: (17, 245, 323)

- Calculate $17\times 15=255$.

- The initial calculation fails to match 245, and thus doesn't continue.

- Option 3: (12, 180, 228)

- Multiply $12\times 15=180$.

- Add $180+48=228$.

- This mimics the pattern of the original set.

- Option 4: (15, 225, 275)

- Calculate $15\times 15=225$.

- Calculate $225+50=275$.

- The additional number doesn't match the pattern precisely.

Option 3 is correct as it follows the same pattern of multiplication and addition as the given set.

Option 3: (12, 180, 228)