Correct Option: A

The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.