TOPIC: Practicing the C Scale on which string?

The article "The Major Scale" shows practicing the A scale on the 5th string. The text states the E scale can be practiced on the 6th or 1st string, D on the 4th, G on the 3rd and B on the second.

Is there a preferred string to practice the C scale on?

You can start on the 3rd fret of the 5th string or the 2nd fret of the 2nd string.

Sorry, I meant to say the 1st fret on the 2nd string.

Thanks.