Which of the following parts is common to classical, steel-string, and electric guitars?

amplifier
pick guard
strings
bridge pins

Amplifier Electric Guitars need one, and most steel strings need one.

Theirs no image re-ask this question and add the picture

Well, in the music industry during the 80s  cyndi lauper took a risk in changing a certain type of music art into something creative with her hair dye and wild hairstyles that were bold, her style was entice and screeching that she actually did her get a lot of hate for it because at that time hair dye and crazy patterns wasn't the norm girl's just wanna have fun for example that changed the work of her genre and a lot of people were influenced by her ways. there was other people who took the dare but not a lot. that itself refers to change in art style, because modern times changed.