I want to know the answer to the following question:
Which pope proclaimed the Immaculate Conception of Mary?
All the background I'm provided with is that "Roman Catholics believe in the Immaculate Conception of Mary, as proclaimed Ex Cathedra by Pope Pius IX in 1854, namely that she was filled with grace from the very moment of her conception in her mother's womb and preserved from the stain of original sin.". Is that enough to answer the question?
Answer: yes