Remove horizontal line on PageBlockSection

How can I get rid of the horizontal line that appears above a page block section in visual force ? I don't want a title or header.
Below is the result and the code.

Also, The 'Other LOB' field still shows even though it's redering condition should hide it if nothing is selected in the multi select field.

User-added image

<apex:pageBlockSection columns="1" id="section1a" showHeader="false" rendered="{!PolicyInformation}" >

<apex:inputField value="{!Comm_Auto_Audit_Sample_Policy__c.Other_LOBs_written_for_insured__c}" rendered="{!OtherLinesOfBusinessWritten}" > 
    <apex:actionSupport event="onchange" reRender="section1a" />
    </apex:inputField>
    
<apex:inputField value="{!Comm_Auto_Audit_Sample_Policy__c.Other_LOB__c}" style="color:blue;" rendered="{!CONTAINS(Comm_Auto_Audit_Sample_Policy__c.Other_LOBs_written_for_insured__c,'Other')}" />  
</apex:pageBlockSection>