This is a 12 mark question, and should be answered in 3 paragraphs, approximately 1 page worth of text. Each paragraph should be a different reason for why Edward IV's death caused a political crisis. For example:
Paragraph 1: Edward IV's death was sudden and unexpected. (Start paragraph by stating your first reason, be clear). Although Edward IV had left two male heirs, in 1483 his eldest son, Edward was only 12 years old. This mean't he needed a protectorate until he came of ruling age, and arrangements hadn't been properly made for this.
Paragraph 2: Factionalism. Richard of Gloucester and his followers were suspicious of the Woodville's and their bids for personal power. Many thought the dowager Queen Elizabeth Woodville would try and advance her own power through her son. Gloucester saw his conquest for the crown as protecting the country from the power hungry Woodvilles.
Paragraph 3: Coronation Arrangements. The Royal Counsel did not deal swiftly with the demands of the Woodville's to have a quick coronation. It enabled Richard of Gloucester to intercept Edward on the road to London and lock him in the tower, to then declare him illegitimate and bolster his own power.