You can watch the TV series The Big C on several streaming platforms:

• Paramount+ (including the Showtime add-on), where all 4 seasons are available to stream with a subscription

• Hulu, which offers all 4 seasons for streaming, with a free trial available for new subscribers

• Amazon Prime Video, where you can watch or buy episodes, though some seasons may require purchase rather than subscription streaming

• Apple TV also offers the series to buy or stream via channels like Paramount+ and Prime Video

In summary, the most straightforward options for full streaming are Paramount+ with Showtime and Hulu. Alternatively, you can purchase episodes on Amazon Video or Apple TV if you prefer to own them