Which ornate cathedral in Saint Petersburg, distinguished by its multicoloured onion domes, marks the exact spot where a reforming emperor was fatally wounded in 1881?

• A Church of the Savior on Spilled Blood ✓
• B Saint Isaac's Cathedral
• C Kazan Cathedral
• D Smolny Cathedral

Built between 1883 and 1907 on the site of Alexander II's assassination, it contains over 7,500 square metres of mosaics.