Solution:
The direction of is given by right handed screw rule.
According to this rule, the direction of caused by about z axis is along .
Hence, option (1) is correct.
Again, according to this rule, the direction of caused by about z' axis is along -
Hence, option (2) is also correct.
As and P closer z'axis, therefore, caused about z' axis is smaller than .
Hence option (3) is also correct.
It is meaningless to add torques about two different axes.
Hence, option (4) is incorrect.