The Salesforce Administrator Brainstorms on the problem and comes up with 3 solutions which can help the Sales Agent in a meeting in which all stakeholders agreed concerning next steps;

1) Decided to create a new field which is a Multi-Select Picklist field which can help the agents store Multiple Product Interest about their Leads.

2) The Admin decided to setup Lead duplicate management using the Email and Mobile numbers of the Leads to track and merge any duplicate after capturing the product of interest for each unique lead.

3) Another Multi-select field would have to be created in Opportunity and mapped to Lead object which will be used to store product of interest after conversion to opportunity.