VS 2010 Proper Syntax for a couple issues

This is a quick one,

I have this code, and when I turn Option Explicit on I get an error.

Me.AddTenantsBindingSource.Filter = "TenantID = " & cboSiteFilter.SelectedValue & ""
Option Explicit on prohibits operands of the type Object for operator '&'

Second one is:
If Me.cboSiteFilter.SelectedValue = Nothing Then
Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity.

Thanks

LB