Take a look at the example below. What is 1 BY 1 doing to the variable SUB? In COBOL

MOVE ZERO TO TOT-AMT. PERFORM 2000-CALCULATE VARYING SUB FROM 1 BY 1 UNTIL SUB > 6. 2000-CALCULATE. COMPUTE TOT-AMT = TOT-AMT + BIMONTH-END (SUB).

A. Decrementing 1 from SUB until > than 6.

B. Multiplying by 1 to SUB until > than 6.

C. Adding 1 to SUB until > than 6.

D. Subtracing 1 from SUB until > than 6.