Which of the following options is not a weed?

Weeds are unwanted plants, which grow in gardens, lawns, etc. Weeds are undesirable and some weeds create nuisance because they have thorns and prickles; some release chemicals, which are toxic and cause skin irritation. They are hazardous if eaten. They crowd out and restrict light to desired crops. They also take away the nutrients available for the desired crops in the soil. Parthenium - “Congress weed”  is a well-known weed. Cyperus – Weed which mainly grows in slow moving water Xanthium – It is also a weed belonging to compositae family. Lentil – Masoor dal is a pulse crop belonging to the legume family. It is consumed as a pulse and is not a weed. Therefore, lentil is not a weed.