An automobile braking system consists of a fluid braking subsystem (foot brake) and a mechanical braking subsystem (parking brake). Both subsystems must fail in order for the system to fail. The fluid braking subsystem will fail if the master cylinder or a hydraulic line fails or all four wheel braking units (front right, front left, rear right rear left) fail. A wheel braking unit will fail if either the wheel cylinder fails (there is one for each wheel) or the brake pad assembly fails (events BP1, BP2, BP3, BP4). The mechanical braking system will fail if the cable system fails or both rear break pad assemblies fail. a) (35 points) Draw the fault tree for this system