It has to be A or B bc c and d are just dumb answers
Rivers/streams are eroded and can be eroded
The compound which is ionic is Kh
Kh is ionic because ionic compound is made between a metal and a non metal. K( potassium) is a metal while H (hydrogen) is a non metal. The bond between potassium and hydrogen form ionic bond whereby potassium loses one electron and hydrogen gain one electron to form an ionic compound.
I think the answer is the moon