Which of the following series of events is listed in proper sequence? a. work begun on erie canal; work begun on baltimore and ohio railroad; b. work begun on national road work begun on national road; c. robert fulton's steamboat, clermont navigated the hudson river; d. work begun on baltimore and ohio railroad the telegraph was put into commercial operation; e. work begun on national road; work begun on baltimore and ohio railroad work begun on baltimore and ohio railroad; f. work begun on national road; work begun on erie canal