Answer:
It is a participial phrase.
Step-by-step explanation:
A participial phrase contains a participial along with other words. So let's look at an example.
"Tidying up her desk for the day, Tina knew she could finally go home." The participial in this sentence is "tidying," and the rest of the words that go along with the participial "tidying" make up the participial phrase. Therefore we know the participial phrase in this sentence is "tidying up her desk for the day".