Unknown property 'VisualforceArrayList.Who'

Hi there,

I'm having this error on my VF page and can't get it resolved. here is the class and page:

    TAsk[] tsk = [select subject, who.name, status, type, activitydate, what.name FROM Task WHERE WhoID IN ( SELECT Contact__c FROM Leadership_position_code__c WHERE Position__c = 'President') and OwnerID = :UserInfo.getUserId()];
    return tsk;

<apex:page controller="Taskleader" showHeader="false" >
<apex:form >
<apex:pageBlock id="pageBlock" Title="Tasks with Presidents">
<apex:pageBlockTable value="{!tsk}" var="tskL" rendered="{!NOT(ISNULL(tsk))}">
<apex:column headerValue="Name" ><apex:outputLink value="https://cs2.salesforce.com/{!tsk.Who.id}" target="_parent">{!tsk.Who.Name}</apex:outputLink></apex:column>
<apex:column value="{!tsk.subject}"></apex:column>
<apex:column value="{!tsk.type}"></apex:column>
</apex:pageBlockTable>
</apex:pageBlock>
</apex:form>
</apex:page>

Thanks!