I think it is A. Hope this helps a lot!!
Taking into account that the Catechism of the Catholic Church describes an indulgence as "a remission before God of the temporal punishment due to sins whose guilt has already been forgiven", the sentences that demonstrate sale of indulgences, (criticized by Protestant) are C and D.
In C. A friar, John Tetzel is exchanging indulgences for money.
In D. Catholics are exchanging indulgences for doing good works
Authors may use keywords or transitions to help readers identify a comparison or a contrast.
Contrasts may contain transitions, such as "despite," "however," "rather," and "but." Comparisons may contain transition, such as "similarly," "in like manner," and "likewise."