Answer:
Complex sentence
Step-by-step explanation:
A complex sentence consists of an independent clause and a dependent clause
independent clause - she managed to sprint across the finish line
dependent clause - even though the runner was tired ( this is considered a dependent clause because it uses a conjunction which depends on another clause for it to make sense.)
So we can conclude that this is a complex sentence because it consist of an independent clause, a dependent clause and a transition word ( even though )