Answer:
Option (B)
Explanation:
Let the five distinct positive integers are a, b, c, d, e.
Average of these five integers is 20.

a + b + c + d + e = 100
If these integers are in the increasing order,
Median of these integers 'c' = 12
If the sum of d and e is the largest then the sum of a and b will be the smallest.
Therefore, the smallest positive integers a and b will be,
a = 1 and b = 2
1 + 2 + 12 + d + e = 100
15 + d + e = 100
d + e = 100 - 15
d + e = 85
Since d will be greater than the median c,
d > c
d > 12
For the largest value of integer 'e', value of 'd' will be minimum.
The least value of d will be = 13
Then, 13 + e = 85
e = 85 - 13
e = 72
{a, b, c, d, e} = {1, 2, 12, 13, 72}
Therefore, the largest possible number is this set will be 72.
Option (B) will be the answer.