When the World Wide Web first became popular in the 1990s, download speeds reached a maximum of about 56 kilobits per second. Approximately how many minutes would the download of a 4.2 megabyte song have taken at that speed? (Note that there are 8000 kilobits in a megabyte.)
Answer Choices
A. 0.6
B. 10
C. 1800
D. 7200
E. 36000