Tech A says that some battery corrosion cannot be seen beneath the insulation of

Tech A says that some battery corrosion cannot be seen beneath the insulation of the cables. Tech B says that an engine cranking voltage drop test is the best way to detect high resistance caused by corrosion. Who
is correct?
Select one:

a. Technician A

b. Technician B

c. Both Technician A and B

d. Neither Technician A nor B