Concept:When two nouns joined by "and" refer to a single item or idea, they take a singular verb.Explanation:"Bread and milk" here means a common breakfast dish, not two separate foods. So it acts as one unit. A singular subject needs a singular verb. Therefore, "is" is correct, not "are". Option A and C use the plural verb "are", which is wrong for a single unit. Option D uses "would be", which changes the meaning and is not the best choice. Only option B correctly uses the singular verb "is" with the singular subject.Answer:B. Bread and milk is a wholesome food.