As Elias was strolling through Costco on a Saturday morning, he tried the samples that were offered throughout the store. When he tasted the Rana Beef and Short Rib Lasagna, he decided to buy it even though he wasn't looking for dinner and had never bought a Rana product before. The lasagna is a$($n$)$

emergency product.

unsought product.

staple.

heterogeneous shopping product.

homogeneous shopping product.