Which one of the following items may be added to a password stored in MD5 to make it more secure？（）

A.Stack vulnerabilities
B.Heap overflows
C.Software overflows
D.Buffer overflows

A.Influencing users to forward a call to a toll number （for example， a long distance or international number）
B.Influencing users to provide personal information over a web page
C.Using an inside facilitator to intentionally forward a call to a toll number （for example， a long distance orinternational number）
D.Influencing users to provide personal information over the phone