How to iterate through Hashtable that has values as List?

Question

I wanted to have multiple values for a single key in my hashtable, so I created key value pair as

Hashtable A = new Hashtable(StringComparer.InvariantCultureIgnoreCase);

List<string> DataList = new List<string>();
DataList.Add(userName);
DataList.Add(firstName);
DataList.Add(lastName);
DataList.Add(Pwd);

if (!A.ContainsKey(ID))
{ 
    A.Add(ID, DataList);
}

For example, my hashtable contains values as

Hashtable A -> Key : 1 , Value : {'A','B','1234','@red'}

Hashtable B -> Key : 2, Value : {'Emma','B','111','@blue'}

I have two hashtables and I want to compare the date using the key. If the key is present in both tables, then I wish to compare the values of that key in both tables. If there is any change, then I output it.

For example, if ID- 1001 is present in both A and B, then I check the list of values in both table for 1001. If for example, A has third value '1234' and B has third value as '111', then I output 111.

Its just a comparison of hashtable but I am stuck at iterating through the values.

foreach(DictionaryEntry details in A)
{
    if(details.Key.Equals(Key of Hashtable B))
    {
        //I want to do something like this if both Hashtables have same key
        string firstname = 'A';
        string lastname = 'B';
        string password ='1234' and so on...
        // I just wish to store the values of first hashtable in some variables so that I can use them further.
    }
}

I tried using foreach but it gave me error that

Foreach statement cannot operate on variables of type 'object' because 'object' does not contain a public definition for 'GetEnumerator'

How do I parse through this list of values in Hashtable?