Pluto was considered the planet.
a. second
c. tenth
b. ninth
d. first

The correct answer is B. Ninth

Explanation:

Since its discovery in the 20th century, Pluto was believed to be the ninth planet of our solar system as this is the ninth most massive object that orbits the sun, and it is located after Neptune which is the eighth planet in our solar system. However, in 2006 Pluto was classified as a dwarf planet because different from other planets such as Earth, Mars, Venus, Saturn, etc. Pluto was not massive enough to clear its orbit, and due to this, it could not be classified as a regular planet. Thus, in the past and until 2006 Pluto was considered the ninth planet.

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.