Final answer:
Both Technician A, who recommends using "Top Tier" gasoline, and Technician B, who suggests keeping the fuel tank at least one-quarter full, are correct. Each provides advice that can help avoid driveability problems in vehicles.
Step-by-step explanation:
The question is which technician is correct about ways to avoid driveability problems in vehicles. Driveability refers to the smooth delivery of power from the engine to the wheels of a vehicle under various operating conditions. Technician A suggests using "Top Tier" gasoline, which is fuel that meets certain performance standards and contains detergents that keep the engine's intake system clean, thus, may contribute to improved driveability.
Technician B recommends keeping the fuel tank at least one-quarter full, which can help avoid issues related to fuel pump cooling and lubrication, potentially preventing driveability problems.
Both technicians provide measures that can contribute to avoiding driveability problems, but they address different elements. Thus, both Technician A and Technician B are correct in their own contexts.