Should i send the variables that WSDL asks or the ones the WebMethod asks?

Question

If i have a C# WebService (it was not me who coded it), that has the following WebMethod:

public string getObjetivos(int intUnidadeID, string strMascara, string strdtInicial, string strdtFinal){...

and the WSDL file specify just 3 of the variables it needs, instead of 4: like this:

...
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="strMascara" type="s:string"/>
<s:element minOccurs="1" maxOccurs="1" name="dtInicial" type="s:dateTime"/>
<s:element minOccurs="1" maxOccurs="1" name="dtFinal" type="s:dateTime"/>
</s:sequence>
...

consuming it via PHP, using (trying to) nusoap with the following (that is not working, i can't find out why):

$intunidadeID = (int)$unidadeid;
require './nusoap.php';
$client = new nusoap_client('http://10.0.0.2/wsmobile/Servicemobile.asmx?WSDL', 'WSDL');
$param = array('intUnidadeID' = $intunidadeID, 'strMascara' = $strmascara, 'strdtInicial' = $strdtinicial, 'strdtFinal' = $strdtFinal);
$answer = $client->call('getObjetivos', array('parameters' => $param));
print_r($answer);

The question is: should i send the 4 variables that the WebMethod asks, or just 3 as the WSDL asks?

This is a curiosity question.