What is the orbital period of Halley's comet?

The orbital period of Halley’s comet is 76 years. 
Halley’s comet was found by Edmund Halley. Halley’s comet is classified as a periodic or a short-period comet, with an orbit lasting for 20 years or less. It returns to Earth every 75 years. According to the calculations, it is going to appear again in 2062. A comet is a member of the solar system. It also revolves around the sun like other planets, but its orbit is not the same. It is made up of dust, rocks, and ice. The solid portion of the comet is known as the head, and the gaseous portion is known as the coma. A coma takes the form of a long tail, which is why it is called a tailed star. When it approaches the sun, it starts to glow due to reflection. Only then can it be seen from Earth.

Therefore, the correct option is 76 years.