It will not make a performance difference. Aim for what is semantically the best code.
As Duncan said... are the strings in any way related? SHould they be perhaps properties of an object, not individual values, or even a struct. EG: if two of them are firstName and lastName, they perhaps would be better as a single object name.
If you really do need to pass four separate arguments to a function... there's a a chance your function is doing too much. What's an example of the function being called? (ie: show us the code).
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Adam