Answer:
Synthetic parallelism.
Step-by-step explanation:
In order to understand the type of parallelism in this verse, we need to know the previous lines. The Book of Psalm 100 1-3 states
1 Shout for joy to the Lord, all the earth.
2 Worship the Lord with gladness;
come before him with joyful songs.
3 Know that the Lord is God.
It is he who made us, and we are his;
we are his people, the sheep of his pasture.
The verse begins with the idea that we, the believers, are God's creation. This idea is then propagated and expanded to show that idea of us being God's belongings/ property. And since we are dependent on Him, this idea is then taken further by implying that "we are his people, the sheep of his pasture".
Synthetic parallelism is when a given idea is expanded and developed into something more in the next lines. So, this line is a synthetic construction of parallelism.