Identify whether this sentence is written in active or passive voice.
The ball was thrown by John.
The sentence "The ball was thrown by John." is written in passive voice.
Complete the following task based on the instruction and optional input provided.### Instruction:
Identify whether this sentence is written in active or passive voice.

### Input:
The ball was thrown by John.

### Output:
The sentence "The ball was thrown by John." is written in passive voice.