The answer is the 3rd choice
Both mass and weight are measured by using scales.
A closed economy<span> is self-sufficient, meaning no imports are brought in and no exports are sent out, the goal being to provide consumers with everything they need from within the </span>economy's borders. An example would be how <span>Brazil's is an unusually </span>closed economy<span> as measured by trade penetration, with exports plus imports equal to just 27.6 per cent of GDP in 2013.</span>
