Final answer:
In April 1192, Richard the Lionheart heard about an assassination plot against him while on the Third Crusade.
Step-by-step explanation:
In April 1192, Richard I, known as Richard the Lionheart, was involved in the Third Crusade, which is a historically significant event. The correct answer to what Richard heard in April 1192 is D) Assassination plot against him. During this period, Richard the Lionheart was known for his interactions and negotiations with Saladin, and the eventual signing of a treaty that allowed Christian pilgrims to visit Jerusalem freely, even though it remained under Muslim control.
Although the Third Crusade did not fulfill all its objectives, it was one of the last successes the crusaders had in the Holy Land. Richard's leadership during the crusade exemplified the chivalric virtue celebrated in Europe.