LONDON — Two Just Stop Oil climate protesters who threw soup over Vincent van Gogh’s “Sunflowers” were sentenced to prison Friday, the latest in a series of hefty punishments for activists in the U.K. On October 14, 2022, Phoebe Plummer and Anna Holland threw two cans of Heinz tomato soup over the masterpiece in the National Gallery in London. Plummer, who faces several other criminal cases for protest actions, was given two years behind bars. Holland was handed 20 months. The painting itself was unharmed, but the 17th-century frame sustained some damage after the soup acted as paint stripper on…