Given the training data for a sample of 10 mortgage applicants in the table below and using the measures of Information Gain and Entropy, determine the descriptive feature which should be at the root node of a decision tree that helps predict whether an applicant will or will not be approved their mortgage application. Give a complete explanation for your choice and show your workings in full. Please read the notes to the table.

Index	mortgage approved	married	age > Median Applicant
0	yes	yes	no
1	yes	yes	no
2	yes	yes	yes
3	no	yes	yes
4	yes	yes	no
5	no	no	yes
6	no	no	yes
7	yes	no	no
8	no	yes	yes
9	no	no	yes

Notes: The variable Mortgage Approved indicates whether the applicant has been approved a mortgage (Yes) or not (No). The variable Married indicates whether the applicant is married (Yes) or not (No). The variable Age > Median Applicant indicates whether the applicants age is greater than the median applicants (Yes) or less than the median applicants (No). Proper explanation required.