According to Acts 23:8, which group says there is no resurrection, nor angels, nor spirits?

Answer: The Sadducees

Paul's mention of the resurrection split the Sanhedrin: Sadducees deny resurrection, angels and spirits, but Pharisees acknowledge them.

“Then Paul, knowing that some of them were Sadducees and the others Pharisees, called out in the Sanhedrin, “Brothers, I am a Pharisee, the son of a Pharisee. It is because of my hope in the resurrection of the dead that I am on trial.””— Acts 23:6 (BSB)