Question #N1348

The history of the development of the computer mouse is long and complex, but it was Douglas Engelbart who is credited with creating the first working prototype in 1964. Engelbart's invention was a revolutionary concept in the field of human-computer interaction, one that would change the way people interact with technology forever. His invention was a small wooden box with two metal wheels that could be moved across a flat surface, and it allowed users to control the cursor on a computer screen by rolling the box. The mouse's invention had a profound impact on the development of computers and the world, and it is still used by millions of people every day.

Which choice provides the best revision of the underlined portion of the passage?
A. was credited with creating the first working prototype in 1964.
B. is credited with creating the first working prototype in 1964.
C. has been credited with creating the first working prototype in 1964.
D. was being credited with creating the first working prototype in 1964.