你正在创建一个Web窗体。你写了如下的代码段去创建一个 SqlCommand对象:现在,你需要显示Customers表中客户的数量。下面那两个代码段能达到此目的?()

A. object customerCount = cmd.ExecuteScalar(); lblCompanyName.Text =customerCount.ToString();

B. int customerCount = cmd.ExecuteNonQuery(); lblCompanyName.Text =customerCount.ToString();

C. SqlDataReader dr = cmd.ExecuteReader(); dr.Read(); lblCompanyName.Text =dr[0].ToString();

D. SqlDataReader dr = cmd.ExecuteReader(); dr.Read(); lblCompanyName.Text = dr.ToString();

参考A, C