3 is B my dude and the reason nobody answered is because thousands of questions are asked every day. So not every question can be answered. It doesn't have to do with being lazy.
Answer:

Explanation:
Let's use Ohm's law:
or
(1)
Where:

We know the value of the voltage V, so we need to find the value of R in order to find I. Fortunately there is a relation between the resistivity of a conductor and its electrical resistance given by:
(2)
Where:

Keep in mind that the electrical resistivity of the gold is a known constant which is
and the cross sectional area of the conductor is calculated as:

Because we have a wire in this case, so we assume a cylindrical geometry.
Now replacing our data in (2)

Finally, we know R and V, so replacing these values in (1) we will be able to find the current:

Water has a high specific heat capacity. Oil has a smaller heat capacity.