<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def option_parser():
 """Option Parser to give various options."""

    usage = '''
             $ ./crawler -d5 <url>
                Here in this case it goes till depth of 5 and url is target URL to
                start crawling.
            '''
    version = "2.0.0"

    parser = optparse.OptionParser(usage=usage, version=version)

    parser.add_option("-l", "--links", action="store_true",
                      default=False, dest="links", help="links for target url")

    parser.add_option("-d", "--depth", action="store", type="int",
                      default=30, dest="depth", help="Maximum depth traverse")
    opts, args = parser.parse_args()

    if len(args) < 1:
        parser.print_help()
        raise SystemExit(1)

    return opts, args