The disjunction, sub(p,1)∨sub(p,2)∨sub(p,3)∨⋯∨sub(p,n) is false if and only if:

a) All sub(p,i) are true for i = 1 to n
b) At least one sub(p,i) is true for i = 1 to n
c) All sub(p,i) are false for i = 1 to n
d) None of the above