Which of the following is not a feature of a national park:
a) Restricted access
b) Built structures
c) Waterfalls
d) Fishing
The option (b) Built structures, is not a feature of a national park.
Complete the following task based on the instruction and optional input provided.### Instruction:
Which of the following is not a feature of a national park:

### Input:
a) Restricted access
b) Built structures
c) Waterfalls
d) Fishing

### Output:
The option (b) Built structures, is not a feature of a national park.