What was one of the main purposes of the first computer systems?
a. performing financial transactions
b. sending personal communications (i. e., e-mail)
c. documenting patient medical information
d. creating media presentations for meetings?

Financial transactions were one of the first purposes of computers. This is where "ticker tapes" came from; early computers were used to keep track of how stocks were performing. Computers in early days used large mainframe systems and punch cards to keep track of this type of data.