Answer: Those who will receive the Holy Spirit are those who have repented and been baptized in the Name of Jesus Christ for the forgiveness of sins, (verse 38).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
Ephesians 1:13-14: "And you also were included in Christ when you heard the Word of Truth, the Gospel of your salvation. Having believed, you were marked in Him with a seal, the promised Holy Spirit, Who is a deposit guaranteeing our inheritance until the redemption of those who are God's possession--to the praise of His glory."