consider how the subject of reform is related to various segments of society captured in middle march?

The novel is set just before the passage of the First Reform Bill of 1832, although historically it was written after the passage of the Second Reform Bill. This is a time when reform was at the forefront; Parliament was deciding who would get to vote, who would take responsibility for the care of the poor, healthcare, and determining pay scales (minimum wage). Obviously this affected the middle and lower classes, but you have to remember that the cost for these reforms would be financed by the upper classes.