from typing import Sequence
from typing import Optional


def ritem_prefix(items: Sequence[str], prefix: str) -> Optional[str]:
    """
    Args:
        items (sequence of str): The items to search
        prefix (str): The prefix to find

    Returns:
        The rightmost element that starts with `prefix`, or `None`
    """
    for item in reversed(items):
        if item.startswith(prefix):
            return item
    return None