What if I were to take a large dictionary with say a billion key value pairs. Now I DOUBLE the number of key value pairs that it contains. How would this impact the time it takes to look up the value for any particular key?

Choice $1$ of $4$:It would cut the lookup time in half

Choice $2$ of $4$:It would approximately double the lookup time

Choice $3$ of $4$:It would approximately quadruple $(4$X$)$ the lookup time

Choice $4$ of $4$:The lookup time would be little changed.