challenge: What figures are depicted in the frescoes flanking the central figure of Ludovica Albertoni in the Altieri Chapel?
  
  A. Saint Clare of Assisi and Blessed Ludovica Albertoni
  B. Saint Peter and Saint Paul
  C. Saint Catherine of Siena and Saint Thomas Aquinas
  D. Saint Francis of Assisi and Saint Anthony of Padua
  Answer: 