If the rabbit population is doubling every year and it starts at 16 rabbits in year 1, we can calculate the population for each subsequent year as follows:
- Year 1: 16 rabbits
- Year 2: 16 × 2 = 32 rabbits
- Year 3: 32 × 2 = 64 rabbits
- Year 4: 64 × 2 = 128 rabbits
- Year 5: 128 × 2 = 256 rabbits
Thus, the rabbit population in year 5 will be 256 rabbits.
Therefore, the correct response is: 256.