Question: Which British shipping line has a full title incorporating Boston Packers, and operated the SS Justicia?

Context articles: Bristol City Line
SS Justicia
White Star Line
Harold Hales
Furness Bermuda Line
Cunard-White Star Line
SL ferries
Atlantic Transport Line
Black Star Line
Union-Castle Line

Bristol City Line was a British shipping line based in Bristol, England that traded from 1704 until 1974.
 From 1760 Bristol City Line also built ships.
SS "Justicia was a British troopship sunk during the First World War.
 She was laid down as SS "Statendam, a 32,234 gross-ton ocean liner built for the Holland America Line by Harland and Wolff in Belfast.
 Before the ship was completed she was acquired by the British government and operated on behalf of the shipping controller by the White Star Line.
The Oceanic Steam Navigation Company or White Star Line of Boston Packers, more commonly known as just White Star Line, was a prominent British shipping company.
Sir Harold Keates Hales MP (22 April 1868 - November 1942) was an eccentric British shipping magnate, politician and founder of the Hales Trophy for the Blue Riband award for the ship with the record for the fastest transatlantic crossing.
 He claimed to be the inspiration for the title character of Arnold Bennett's "The Card".
 He was the sole proprietor of Hales Brothers, an export and import shipping line.
The Furness Bermuda Line was a British shipping line that operated during the 20th century.
 Affiliated with the Furness Withy conglomerate, it ran cruises from New York City primarily to the British territory of Bermuda.
Cunard White Star Line, Ltd., was a British shipping line which existed between 1934 and 1949, It was created as an operating company to control the joint shipping assets of the Cunard Line and the White Star Line after both companies experienced financial difficulties during the Great Depression.
 Cunard White Star controlled a total of twenty-five large ocean liners (with Cunard contributing fifteen ships and White Star ten).
 Both Cunard and White Star were in dire financial trouble, and were looking to complete enormous liners: White Star had Hull 844 – RMS "Oceanic III" – and Cunard had Hull 534, which would later become  .
SL ferries (short for Swedish "Skandinavisk Linjetrafik" or Scandinavian Line Traffic) was a shipping line that operated with car ferries in the central part of Øresund, between Copenhagen, Port of Tuborg, Zealand, Denmark and Landskrona, Scania, Sweden.
 The shipping line was to sail this route between 1951 and 1980 During the first ten years of operation, the SL ferries was a Danish owned shipping line, but in 1961 SL was bought by "Stockholms Rederi AB Svea".
 The new owners also owned the LB (car ferries) which since 1955 operated at the HH Ferry route between Helsingør (45 km north of Copenhagen) and Helsingborg (25 km north of Landskrona), the first challenger of the "de facto" monopoly at that route which DSB had enjoyed since 1882.
The Atlantic Transport Line was an American passenger shipping line based in Baltimore, Maryland.
 In 1901 the company was folded into the International Mercantile Marine shipping trust (IMM).
 The line developed with railroad support as an offshoot of Bernard N. Baker's Baltimore Storage and Lighterage Company in 1881.
 Although American owned, the Atlantic Transport Line operated from Britain, with British registered and manned vessels, most of which were British built.
 General cargo, live cattle and small numbers of passengers were carried from Baltimore and Philadelphia to British ports and the line developed an excellent reputation for shipping valuable horses.
 A full-scale weekly passenger service between New York and London commenced in 1892 and today the line is best remembered for its exclusively first class direct London to New York passenger/cargo service operated by its four Minne class ships, SS "Minneapolis", SS "Minnehaha", SS "Minnetonka" and SS "Minnewaska" from 1900 to 1915.
The Black Star Line (1919−1922) was a shipping line incorporated by Marcus Garvey, the organizer of the Universal Negro Improvement Association (UNIA), and other members of the UNIA.
 The shipping line was created to facilitate the transportation of goods and eventually African Americans throughout the African global economy.
 It derived its name from the White Star Line, a line whose success Garvey felt he could duplicate.
 Black Star Line became a key part of Garvey's contribution to the Back-to-Africa movement.
 It was one among many businesses which the UNIA originated, such as the Universal Printing House, Negro Factories Corporation, and the widely distributed and highly successful "Negro World" weekly newspaper.
The Union-Castle Line was a British shipping line that operated a fleet of passenger liners and cargo ships between Europe and Africa from 1900 to 1977.
 It was formed from the merger of the Union Line and Castle Shipping Line.