What Are The Letters That Requires Close Study Because Of The Introduction Of The Curved Lines?

What are the letters that requires close study because of the introduction of the curved lines?

 

A. The letter “S” is a good example, as it has two curves in its shape and one curve at the end. It can be seen from this picture:

B. Another example would be the letter “T” which also has three different types of curves. This time we have four curves on top of each other to form the T-shape. You can see an image here:

C. A third type of letter with multiple curves is the letter “Z”. In this case there are five curves forming the Z-shape. Here you can find an image showing all these shapes:

D. Finally, lets look at another letter "U". There are six curves making up the U-shape. These are shown below:

E. So what do you think about those examples? Do they make sense or not? If yes then why? And if no then why?