Which code segment should you use?

You are creating an endpoint for a Windows Communication Foundation service by using Microsoft .NET Framework 3.5. You create the endpoint by using a custom binding. You write the following code segment.

BasicHttpBinding binding=new BasicHttpBinding();
binding.Security.Message.ClientCredentialType=
BasicHttpMessageCredentialType.Certificate;
binding.Security.Mode=BasicHttpSecurityMode.Message; CustomBinding cb=new CustomBinding(binding);
BindingElementCollection bec=cb.CreateBindingElements();

You need to prevent the custom binding from making a persistent connection to the service endpoint.
Which code segment should you use?

A.
cb.SendTimeout=TimeSpan.Zero;

B.
binding.ReceiveTimeout=TimeSpan.Zero;

C.
foreach (BindingElement bindingElement in bec)
{
HttpTransportBindingElement element= (HttpTransportBindingElement)bindingElement;
element.KeepAliveEnabled=false;
}//foreach

D.
foreach (BindingElement be in bec)
{
if (be is HttpTransportBindingElement)
{
HttpTransportBindingElement httpElement= (HttpTransportBindingElement)be;
httpElement.KeepAliveEnabled=false;
}//if
}//foreach