Concept:The sum of two integers is odd only when one integer is odd and the other is even.Explanation:Out of 20 consecutive positive integers, there are exactly 10 odd and 10 even integers.Total number of ways to choose 2 integers from 20 is:(220​)=190.Number of favourable ways to choose 1 odd and 1 even integer is:10×10=100.Therefore, the required probability is:190100​=1910​.Answer:Option A: 1910​.