Which of the following would decrease the resistance to the flow of an electric current through a body?

A. Shortening the conductor

B. Lengthening the conductor

C. Using a conductor with a smaller cross section

D. Heating the conductor

R = ρ L/A. R = resistance, ρ = resistivity, L = length of the conductor. A = area of the conductor. Resistance is directly proportional to the length of the conductor. So if length of the conductor is decreased, resistance will also decrease. Hence A is the correct option