Which of the following is the BEST example of how email can be used to generate new leads?

Which of the following is the BEST example of how email can be used to generate new leads?
  A)  Contacts replying to your email with new information about themselves.
  B)  Contacts forwarding your email to their networks.
  C)  Emails tailored to recipients through the use of personalization tokens builds trust in your organization.
  D)  High CTA click-through rate on a website page linked to in an email.