Solution:
Let us check for the possibilities of elements of B.
Now since the sum of no two elements is 203, there will be some constraints while selecting the elements.
Let 0, 1 and 2 belong to B. Then there is no other element with which they combine to give a sum of 203. So they can easily belong to B without limiting the presence of any other element.
Let 3 belong to B. Then 200 cannot belong to B because their sum will give 203.
So either 3 or 200 will be in B.
Similarly either 4 or199, 5 or 198, 6 or 197............100 or 103, 101 or 102 can belong to B.
So the possible elements of B are {0,1,2, 3,...............101} or {0,1,2, 200, 199, 198............,102}.
In any case there will be a maximum of 102 elements in B.

The correct answer is (C).