In vehicles equipped with abs, the driver's foot must remain firmly on the to activate the abs.

ABS is activated when the computer detects the wheel[s] are decellarating too quickly. It then pumps the brakes about 15 times a second. People can't pump the brakes anywhere near that fast, so it's better that the driver just keep the brake pedal depressed and let the machine take care of it.

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Answer (b) the meter will display a negative sign;