The direction in which an electrical signal is carried in a typical multi-polar neuron is:
Dendrites, cell body, axon
Specialized projection of neurons are dendrites and axon. The central part of neuron is cell body. So, the electrical signal is carried in a direction that first dendrites carried the signal then it goes towards cell body and then to axon.
The density of an object can be calculated using the formula Density = Mass/Volume. In this case however we are searching for the volume and must rearrange the formula so that we are solving for the volume. If you multiply both sides by volume and then divide both sides by mass you end up with the equation Volume = Mass/Density.
Volume = 1500g/1.5g/cm^3
Volume = 1000 cm^3
The answer is A and E.
Hope this helps! :D