How do you activate the trace option for the R3SZCHK program? Please choose the correct answer.

How do you activate the trace option for the R3SZCHK program? Please choose the correct answer.
A . Set environment variable R3SZCHK_TL=<1…4>
B . Call R3S2CHK with parameter -TL=<1…4>
C . Call R3S2CHK with parameter -TRACE_LEVEL=<1.. A>
D . Set environment variable R3S2CHK_TRACE_LEVEL=<1 4>

Answer: A