def extract_arxiv_links(urls):
    """
    Try to find an arXiv link from a given list of URLs.

    :param urls: A list of URLs.
    :returns: First matching arXiv URL, or ``None``.
    """
    arxiv_urls = [url for url in urls if "://arxiv.org" in url]
    if len(arxiv_urls) > 0:
        return arxiv_urls[0]
    else:
        return None