A car manufacturer discovers that the purchase journey is typically one-year long, involves several media channels and is followed by a dealership visit that ends with a purchase at the dealership. Historically, sales are mostly influenced by the quality of the customer service experience. The manufacturer has a KPI of driving incremental customers to its website.

What measurement solution should be used?

A. Last-touch attribution

B. A/B test

C. Conversion Lift

D. Even credit attribution

(with explanation pls)