Get only one product category woocommerce

I have to get and show only one category name from a product. I have almost read everything and tried everything.

<?php 
$term =  get_the_terms( $post->ID, 'product_cat' );
foreach ($term as $t) {
   $parentId = $t->all;
   if($parentId == 0){
     echo $t->name;
   }else{
     $term = get_terms( 'product_cat', array('include' => array($parentId)) );
   }
}

?>

It shows one long string with all the category names. How should I get only one category and show its name.

Before I begin, just one note, there is no property called $all in get_the_terms. Here are the available fields which you can use

stdClass Object
(
    [term_id] =>
    [name] =>
    [slug] =>
    [term_group] => 
    [term_order] => 
    [term_taxonomy_id] =>
    [taxonomy] =>
    Get only one product category woocommerce => 
    [parent] =>
    [count] =>
    [object_id] =>
)

I’m not very sure what you want to achieve looking at your code, but if you need only one term from the returned array, you can do something like this: (NOTE: get_the_terms returns a WP_ERROR object on invalid taxonomy, so you want to check that, also check whether or not you have terms retrieved)

$terms =  get_the_terms( $post->ID, 'product_cat' );
if ( $terms && ! is_wp_error( $terms ) ) {
    echo $terms[0]->name;
}

$terms[0] will return the first term in the returned array.