Benjamin franklin invented many useful and practical objects including bifocal glasses and lightning rods. (2) franklin also invented some things for entertainment. (3) the glass armonica is a musical instrument that franklin invented. (4) the armonica is made of glass bowls. (5) the bowls lie in a wooden chest, making it look somewhat like a piano. (6) the instrument is played by sitting in front of it, placing moist fingers on the bowls, and turning the bowls. (7) franklin got the idea for his instrument when he saw a concert where the musician rubbed his fingers along the rims of drinking glasses.

which of these replacements for sentence 4 best provides specific details?

a)
the armonica is made of glass bowls that are put onto a metal rod.

b)
the armonica is made of a few different glass bowls that are on a rod.

c)
the armonica is made of different sized glass bowls that are strung on a metal rod.

d)
the armonica is made of different sized bowls that are connected together by a rod.