GATE CS 2010 Q44 — Software Engineering (Historical)

The following program is to be tested for statement coverage:

begin
    if (a==b) {S1; exit;}
    else if (c==d) {S2;}
        else {S3; exit;}
    S4;
end

The test cases T1, T2, T3 and T4 given below are expressed in terms of the properties satisfied by the values of variables $a,\:b,\:c$ and $d$. The exact values are not given.

T1: a, b, c and d are all equal

T2: a, b, c and d are all distinct

T3: a = b and c != d

T4: a != b and c = d

Which of the test suites given below ensures coverage of statements S1, S2, S3 and S4?