Slow Stochastics - which is the right one?

Hello,

I am a newbie in TA. I would like your help in clarifying which one is a "slow stochastic".

In amibroker there are two in built stochastics (formulas mentioned below each indicator)

A) Stochastic %D

periods = Param( "Periods", 15, 1, 200, 1 );
Ksmooth = Param( "%K avg", 3, 1, 200, 1 );
Dsmooth = Param( "%D avg", 3, 1, 200, 1 );
Plot( StochD( periods , Ksmooth, DSmooth ), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );

_SECTION_BEGIN("Stochastic %K");
periods = Param( "Periods", 15, 1, 200, 1 );
Ksmooth = Param( "%K avg", 3, 1, 200, 1 );
Plot( StochK( periods , Ksmooth), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );
_SECTION_END();

B) Stochastic %K

periods = Param( "Periods", 15, 1, 200, 1 );
Ksmooth = Param( "%K avg", 3, 1, 200, 1 );
Plot( StochK( periods , Ksmooth), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );

and I have this one more custom formula

C) Slow Stochastic

_SECTION_BEGIN("Stochastic Slow");
periods = Param( "Periods", 15, 1, 200, 1 );
Ksmooth = Param( "%K avg", 3, 1, 200, 1 );
Plot( StochK( periods , Ksmooth), "%K"+_PARAM_VALUES(), ParamColor( "%K color", colorCycle ), ParamStyle("%K style") );
Dsmooth = Param( "%D avg", 3, 1, 200, 1 );
Plot( StochD( periods , Ksmooth, DSmooth ), "%D"+_PARAM_VALUES(), ParamColor( "%D color", colorCycle ), ParamStyle("%D style") );

if( Status("action") == actionCommentary )
{
printf("(Interpretation is not available yet)");
}
_SECTION_END();

My confusion which is a Slow Stochastic?

Kindly advise.

Regards,

JHS