Final answer:
In a manual transmission, the shift lever controls what gear the transmission is in.
Step-by-step explanation:
In a manual transmission, the shift lever controls what gear the transmission is in. The shift lever is located in the center console of the car, typically between the two front seats. By moving the shift lever to different positions, the driver can engage different gears in the transmission.
The clutch pedal is used to disengage and engage the engine from the transmission, allowing for smooth gear changes. The accelerator pedal controls the speed of the vehicle by increasing or decreasing the engine's power. The brake pedal is used to slow down or stop the vehicle. While all these components are important for operating a manual transmission car, it is the shift lever that specifically determines what gear the transmission is in.