Converting columns into rows with different values

I have a CSV file with 16 columns.

The first 10 (A-J) are contact information, the last 6 are different phone numbers, sometimes for the same contact.

My objective is to create duplicates of the first 10 columns with the new 11th column (K labeled PHONE) representing one phone number from the last 6 columns.

I am looking to keep all values from A to J as is in their own columns (no merging)Value in column K should have only one phone number.

Here is a link to a sample of data with “before”: what the original sheet was and “after” an example of what the result should look like.