Possible Clues:

• Select as an alternative
• ___-in (like some mailing lists)
• ___ for (pick)
• Make a choice, with 'for'
• Choose from melting pot
• Pick an alternative
• Settle on (with "for")
• 'Chews for this, by the sound of it (3)'
• Elect, with ''for''
• ___ out (stop subscribing)