Explanation:

- The relationship between the numbers is as follows:

- 15 : 135: Multiply 15 by 9 (15 × 9 = 135).

- 18 : 189: Multiply 18 by 10.5 (18 × 10.5 = 189).

- Therefore, we need to find the relative multiplier for the sequence 16 : ?.

- Using the pattern in the options and examples, let's consider multiplying 16 by a pattern number.

- The pattern is not entirely consistent as each number has varying multipliers.

- Evaluating the given options for 16:

- Option 1, 152: 16 × 9.5 ? 152.

- Option 2, 121: 16 × 7.5 ˜ 121.

- Option 3, 131: (no apparent pattern).

- Option 4, 141: (no apparent pattern).

The answer can follow a multiplying pattern fairly aligning with one of the known options.

Option 4: (141)