Is Each of the Following Compounds a Covalent Compound or an Ionic

Is each of the following compounds a covalent compound or an ionic compound? Write the answer in the blank.
A) C₅H_{12 _____}
B) Fe(OH)_{3 _____}
C) HClO_{3 _____}
D) K₃PO_{4 _____}
E) (NH₄)₂SO_{4 _____}