The correct answer is A. wheat, barley, peas, rapeseed, mustard, grams.
Rabi crops are winter crops that are grown in the northern hemisphere during the winter season. They are sown in the autumn and harvested in the spring. Rabi crops are grown in areas with a temperate climate, where the winters are cold and the summers are warm.
The main examples of Rabi crops are wheat, barley, peas, rapeseed, mustard, and grams. Wheat is a cereal crop that is used to make bread, pasta, and other food products. Barley is a cereal crop that is used to make malt, which is used in brewing beer and whisky. Peas are a legume crop that is used to make peas, pea soup, and other food products. Rapeseed is an oilseed crop that is used to make vegetable oil. Mustard is a cruciferous vegetable that is used to make mustard sauce and other food products. Grams are a legume crop that is used to make dal, which is a staple food in India.
The other options are incorrect because they do not include all of the main examples of Rabi crops. Option B does not include peas, rapeseed, or mustard. Option C does not include wheat, barley, or rapeseed. Option D includes all of the main examples of Rabi crops, but it is not the most concise answer.