Concept:Numerals are symbols for numbers. They should be introduced only after children understand the number concept.Explanation:Teaching zero as a symbol before understanding can cause confusion. Children may think the shape of ‘0’ defines zero, instead of understanding zero as a quantity. Number sense means a flexible understanding of numbers and operations. Zero represents ‘nothing’ or an empty set. Children first need to grasp this idea through real objects and activities. Once they develop number sense, they can correctly interpret the symbol ‘0’. Therefore, zero should be introduced only after children have built a solid number sense.Answer:D. Zero should be introduced after children develop number sense