Which one of the following DATA step programs creates an equivalent SAS data set THREE?

Given the following SAS data sets ONE and TWO:

ONE TWO

NUM CHAR1 NUM CHAR2

1 A1 2 X1

1 A2 2 X2

2 B1 3 Y

2 B2 5 V

4 D

The following SAS program is submitted creating the output table THREE:

proc sql;

create table three as

select one.num, char1, char2

from one, two

where one.num = two.num;

quit;

THREE

NUM CHAR1 CHAR2

2 B1 X1

2 B1 X2

2 B2 X1

2 B2 X2

Which one of the following DATA step programs creates an equivalent SAS data set THREE?
A . data three;
merge one two;
by num;
run;
B . data three;
set one;
set two;
by num;
run;
merge one two;
by num;
run;
C . data three;
set one;
set two;
by num;
run;
by num;
run;
D . data three;
set one;
do i = 1 to numobs;
set two(rename = (num = num2)) point = i
nobs = numobs;
if num2 = num then output;
end;
drop num2;
run;