There is a lot of controversy surrounding the invention

Choose the letter A, B, C or D to complete the passage below
There is a lot of controversy surrounding the invention __________ (6) the telephone. There have been court cases, books, and articles generated about the subject. Of course, Alexander Graham Bell is the father of the telephone. After all it was his design that was first __________ (7), however, he was not the first inventor to come up __________ (8) the idea of a telephone.
Antonio Meucci, an Italian immigrant, began developing the design of a talking telegraph or telephone __________ (9) 1849. In 1871, he filed a caveat (an announcement of an invention) for his design of a talking telegraph. Due to hardships, Meucci could not renew his caveat. His role in the invention of the telephone was overlooked until the United States House of Representatives __________ (10) a Resolution on June 11, 2002, honoring Meucci's contributions and work. You can read the resolution (107th Congress, H Res 269) on Congress.gov.
To make matters even more interesting some researchers suggest that Elisha Gray, a professor at Oberlin College, applied for a caveat of the telephone on __________ (11) same day Bell applied for his patent of the telephone- these gentlemen didn't actually visit the Patent Office, their lawyers did __________ (12) their behalf. In Historical First Patents: The First United States Patent for Many Everyday Things (Scarecrow Press, 1994), Travis Brown, reports that Bell's lawyer got to the patent office first. The date was February 14, 1876. He was the fifth entry of that day, __________ (13) Gray's lawyer was 39th. Therefore, the U.S. Patent Office ___________ (14) Bell with the first patent for a telephone, US Patent Number 174,465 rather than honor Gray's caveat. _________, (15) some authors dispute this story and suggest that there was malfeasance by certain individuals at Patent Office, and possibly Bell himself.