These are my reasons:
The National Museum of American History owns Harley-Davidsons of various vintages on account of having
evolved into an American touchstone.
A. on account of having - on account of is ackwards for this sentence
B. on account of their having - the same in B
C. because they have - correct. It clearly refers to the Harley-Davidsons
D. because of having - it's not clear. you could understand that the museum has evolved into an American touchstone.
E. because it has - it changes the meaning of the sentence. In this case, the museum has evolved into an American touchstone.
I think I deserve kudos
"Life’s battle doesn’t always go to stronger or faster men; but sooner or later the man who wins is the one who thinks he can."
My Integrated Reasoning Logbook / Diary: my-ir-logbook-diary-133264.html