Answer:
1.5 em
Explanation:
When the lowest margin towards 1st component is 1.5 em as well as the upper margin for this with the component here is 1 em thus 1.5 em would be the margin between certain two components when rendering a web page in such a browser because when the page is submitted in the browser then the margin should be 1.5 em (according to 1st one) larger between both of the components.