def METHOD_NAME(dataset):
    current_max_size = 0
    primary_tensor_name = None
    for tensor_key, tensor in dataset.tensors.items():
        max_shape = tensor.meta.max_shape
        max_size = np.prod(max_shape)
        if max_size > current_max_size:
            current_max_size = max_size
            primary_tensor_name = tensor_key
    return primary_tensor_name