Determine if the given sentence is passive or active.
The cat was chased by the dog.
The sentence "The cat was chased by the dog" is passive. In a passive sentence, the subject (in this case, "the cat") is acted upon by the verb.
Complete the following task based on the instruction and optional input provided.### Instruction:
Determine if the given sentence is passive or active.

### Input:
The cat was chased by the dog.

### Output:
The sentence "The cat was chased by the dog" is passive. In a passive sentence, the subject (in this case, "the cat") is acted upon by the verb.