All stem of the plants and trees are green in colour when they young. But why does the colour of the stem change to brown as they grow older

What factor contributed most to the beginning of the women’s rights movement in the united states during the mid 1800s? a dramatic increase in women’s participation in the workforce b a shift in social attitudes brought on by increased sectional tensions c the experience of gender discrimination within reform movements d the granting of voting rights to african american men