Change the following sentence from active to passive voice:

Careless driving causes many accidents.

Many accidents are caused by careless driving.

The correct answer is Option (2) - Many accidents are caused by careless driving.

The given sentence is in the active voice:

"Careless driving causes many accidents."

To change it to passive voice:

1. Identify the object: "many accidents"
2. Identify the verb: "causes" (simple present tense)
3. Convert the verb to passive form: "are caused" (since "accidents" is plural)
4. Retain the subject as the agent introduced by "by": "by careless driving."

Thus, the correct passive sentence is: "Many accidents are caused by careless driving."