c.)meter
Explanation:
Among the choices given, only the meter is a fundamental unit of the metric system. In particular, meter is the fundamental unit of the length, and one meter is defined as the length of the path travelled by light in vacuum during a time interval of 1/299792458 second.
Yard is another unit of length, equal to approximately 0.91 m.
Liter is a unit of volume.
Fathom is another unit of length, equal to approximately 1.83 m.
