Answer: 34500%.
Explanation:
When we convert a number into percent , we multiply it by 100.
For example: To convert 0.56 into percent, we have

Let's take one more example , to convert 12 into percent , we have

The given number : 345
So to convert 345 into percent , we just multiply it by 100 , we get

Hence, 345 is 34500%.
Thus , the correct answer is 34500%.