get all xml attributes from a node using xlst 1.0 transformation

I have the following xml and i would like to only filter the attributes of node "A" using XLST version 1.0 transformation

<A a_1="a1" a_2="a2"/>
<B>
 <C>
    hello
 </C>
</B>

I can use the following XLST transformation, but i'm looking if there is a way to get all the attributes without going one by one

<A a_1="{A/@a_1}" a_2="{A/@a_2}">

The output response would look like

<A a_1="a1" a_2="a2">

XSLT is very much sensitive to context. With a well-formed input such as:

<A a_1="a1" a_2="a2">
  <B>
    <C>
    hello
 </C>
  </B>
</A>

you can use this stylesheet:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml"  indent="yes"/>

<xsl:template match="/A">
    <xsl:copy>
        <xsl:copy-of select="@*"/>
    </xsl:copy>
</xsl:template>

</xsl:stylesheet>

to get:

<?xml version="1.0"?>
<A a_1="a1" a_2="a2"/>