Which of the following is different from the rest?

Green gram, Pea, Corn, Kidney beans

​Green gram: A type of pulse, also known as mung bean.

Pea: A type of pulse, commonly categorized as a legume.

Corn: A cereal grain, not a pulse or legume.

Kidney beans: A type of pulse, also categorized as a legume.

Corn is the only one that is a cereal grain, while the others are all pulses/legumes.

So, Option: B (Corn) is different from the rest.

Thus, the correct option is: (b)