We have to remember the nomenclature for redox reactions:
<u>Oxidation</u>:
<u>Reduction</u>:
So, all the answer options are written as <u>reductions</u>. Therefore the voltage values, in this case, would be the <u>reduction potentials</u>. If we have a higher (<u>positive</u>) potential the compound would be <u>more inclined to a reduction</u> and vice-versa if we have a smaller potential (<u>negative</u>) the compound would be <u>more inclined to oxidation</u>.
In this case, the <u>most negative value</u> is for Na+, so this atom would be more easily <u>oxidized</u>.
Timbuktu was considered a MASSIVE trade center in Mali. That is how all of the foreign goods came into the kingdom. It also had education centers which was very important in Mali.