Answer:
an independent clause.
Explanation:
In the sentence there are two clauses:
"When we get out of school early" is a subordinate clause. "my mother picks me up" is an independent clause.
The group of words that has both a subject and verb and expresses a complete thought will be called an independent clause
An independent clause by definition can be written and in itself expresses an idea completely, so my mother picks me up" is an independent clause. whereas "When we get out of school early" is a sentence that lacks complete expression and if written solely it will feel that something else is missing.
Therefore the other details will be needed.
