What form class is the bold word? Our (teachers) are very happy with our results.
a) adjective
b) adverb
c) verb
d) noun

Noun

Explanation:

An verb is an action word

An adverb describes a verb

An adjective describes a noun referring to traits of it (I'm free writing this not googling the exact definition so prob slightly wrong on this definition.

it's noun

either a donut or a sphere or a pancake or a flat sphere. it depends on where the vertical line is.

if the line goes through the center of the circle and is perpendicular to a diameter containing the center, then you get a flat circle.

if the line and the diameter of a the circle meet in the center of the diameter and at an angle, you get a pancake.

if the line is on the circumference of the circle and is at right angles   to the circle you get a ring.

if the line contains the diameter, you get a sphere.

the the line is parallel to the diameter and touches the circumference, you get a donut.