Who give the suggestion of digging the trench around the city of Madinah at the time of “battle of Khandaq”...? Mcqs

Who give the suggestion of digging the trench around the city of Madinah at the time of “battle of Khandaq”...?

(A) Abu Bakr Siddique (R.A)

(B) Salman Al-Farsi (RA)

(C) Khalid bin Waleed (R.A)

(D) None of these