3
Step-by-step explanation:
The chord diagram shows that the 1st finger is placed on the 1st fret of the 2nd string, the 2nd finger is placed on the 2nd fret of the 3rd string, and the 3rd finger is placed on the 2nd fret of the 1st string. There is a zero over the 4th string, indicating that this string should not be played. There are x's on the 5th and 6th strings, indicating that these strings should not be played. Therefore, the player would only strum the 2nd, 3rd, and 1st strings.