Which of the following is not approximately equivalent to one of the metric units: 1 kilometer, 1 meter, 1 kilogram, or 1 liter?

0.6 mile

1 quart

1 pound

1 yard

A.
Note that 1 mile = 1.609 km.
Therefore
0.6 miles = 0.6*1.609 km = 1 km (approximately).

b.
Note that 1 US quart = 0.9463 liters.
Therefore
1 quart = 1 liter (approximately).

c.
Note that 1 pound = 0.4536 kg
Therefore 1 pound is not even approximately equal to one kilogram.

d.
Note that 1 yard = 0.9144 m.
Therefore
1 yard = 1 m (approximately).

1 pound is not approximately equivalent to one of the metric units.