Concept:The odd number is the one that does not share a common property with the others. Here the property is that the sum of digits equals 9, or equivalently the number is divisible by 3.Explanation:Check each number: For 28, sum of digits 2+8=10, not 9. Also 28 is not divisible by 3.For 45, sum 4+5=9, divisible by 3.For 63, sum 6+3=9, divisible by 3.For 36, sum 3+6=9, divisible by 3.Only 28 differs in both properties.Answer:Option A: 28