aggregation and composition

Below is an example.

public class Card
    {
        public string CardNumber {get;set;}
        public string CardHolderName { get; set; }
        public DateTime CardExpiryDate { get; set; }
        public string CvvNumber { get; set; }
    }

    public class Visa
    {
        public Card card = new Card();
        public string SecuredToken { get; set; }
        public bool IsInternationlValid { get; set; }
    }

    public class Master
    {
        public Card card = new Card();
        public string PinNumber { get; set; }
        public bool IsInternationlValid { get; set; }
        public bool IsAllowedInNepal { get; set; }
    }

Thanks
Alok Saxena