What Of Following Of Products Have A Cross Price Elasticity Of Negative Demand

What of following of products have a cross-price elasticity of negative demand ?

  1. High-speed internet access and an online streaming service for TV shows
  2. Jelly and jam
  3. Dishwashers and houseplants
  4. Pens and pads of paper
  5. A Porsche 911 and a BMW i8