Can you please explain how to answer this question?

Q2: Using capital letters of the alphabet, do each of the following, or else explain why this is not possible. Each word in parts a) to d) should be at least 4 letters long and the word-lengths among these four words need to be all different.

a) Find a word that has a horizontal line of symmetry when its letters are written horizontally.

b) Find a word that has a vertical line of symmetry when its letters are written vertically below each other.

c) Find a word with a horizontal line of symmetry when its letters are written horizontally and a vertical line of symmetry when its letters are written vertically below each other.

d) Find a word that has a centre of rotation with angle of rotation 180 when its letters are written horizontally.

e) Write your word from d) vertically. Does it still have a centre of rotation with angle of rotation 180? Why should this be so?

f) What aspect of this problem is important to consider? Record three troubles you came across while constructing these words.