C)    2, 3 and 4   

1.    Furs were increasingly shipped through the Hudson Bay trading posts.
2.    The mother country's needs for wheat made it possible to export agricultural surplus at the
        beginning of the 19th century.    Correct !
3.    The export of timber to Britain increased because of Napoleon's blockade. Correct !
4.    The number of jobs for lumber jacks, raftsmen and dock workers increased. Correct !
5.    Soil exhaustion and poor farming techniques caused an agricultural crisis by the 1830s.
6.    The city of Montreal was no longer the commercial centre of the fur trade.