mongoc driver: write query in mongoc driver in C

Question

I have a collection named example_Collection with data of format:

{
{
 "_id": ObjectId("100"),
 "source_timestamp":{
   "sec" : 90000
  }
 }
 {
 "_id": ObjectId("200"),
 "source_timestamp":{
   "sec" : 95000
  }
  {
 "_id": ObjectId("300"),
 "source_timestamp":{
   "sec" : 100000
  }
 }
 }

}

I need to find the documents which has sec from greater then 9000 and small than 10000.

For this mongoquery is working: db.example_Collection.find({"source.timestamp.sec":{$gte:9000,$lt:10000}})

but how to write the same query in mongo C driver?